System for a minimally-invasive, operative gastrointestinal treatment background

ABSTRACT

A system for performing minimally invasive procedures in a working space within a body lumen of a patient including a flexible catheter configured to receive a working instrument therethrough. The flexible catheter has a working space expanding system positioned at the distal portion, the working space expanding system including first and second flexible elements movable from a non-expanded insertion position to an expanded position forming an expanded region to expand the working space within the body. The first and second flexible elements are connected at a distal region by a coupling structure. A stabilizing member stabilizes the distal portion of the flexible catheter.

This application is a continuation of U.S. application Ser. No.16/936,608, filed Jul. 23, 2020, which is a continuation of U.S.application Ser. No. 15/261,930, filed Sep. 10, 2016, which is acontinuation in part of U.S. application Ser. No. 14/622,831, filed Feb.14, 2015, now U.S. Pat. No. 10,595,711, which is a continuation in partof U.S. application Ser. No. 13/913,466, filed Jun. 9, 2013, now U.S.Pat. No. 9,186,131, which is a continuation in part of U.S. applicationSer. No. 12/970,604, filed Dec. 16, 2010, now U.S. Pat. No. 8,506,479,which claims priority under 35 U.S.C. § 119 to U.S. ProvisionalApplication Ser. No. 61/287,077, filed Dec. 16, 2009, and U.S.application Ser. No. 13/913,466, filed Jun. 9, 2013, now U.S. Pat. No.9,186,131 is a continuation in part of U.S. application Ser. No.13/531,477, filed Jun. 22, 2012, now U.S. Pat. No. 8,932,211. The entirecontents of each of these applications are incorporated herein byreference.

FIELD OF THE INVENTION

This application is directed to endoscopic systems and methods forexpanding body lumens and for treating tissue within the body lumen.

DESCRIPTION OF THE RELATED ART

Endoscopic procedures involving the gastrointestinal system offeradvantages over conventional surgery in that they are less invasive andmay provide visualization.

One current problem includes a lack of technology for an optimalminimally-invasive expansion of a stable, working space adjacent to thetarget tissues that could otherwise collapse around the target lesion ordefect during an operative treatment. Having the ability to effectivelyexpand and optimally reconfigure or reshape the working space couldmarkedly facilitate an intra-luminal operation. A better expanded,stable and optimally configured working space allows the instruments andendoscope to be independently manipulated and properly visualized aroundthe target tissue.

Another current problem includes a lack of an endoscopic technology fornot only expanding, but also affixing and reshaping, both the targettissue and surrounding tissue. In a bowel, for example, such a stableoperative space could include a space that is non or less collapsible,with limited peristalsis or aperistaltic, and/or affixed at a particularpoint in the abdominal cavity. The fixed point can be considered fixedin relation to, for example, a fixed body point in the patient, such asthe patient's hip. Significant bowel movement is considered to be highlyundesirable during an intra-luminal operation on the bowel, for example,since it may create a challenging, unstable operative environment. Suchbowel movement is normal, of course, even in a sedated patient and canbe caused, for example, by bowel collapse from an air leak, peristalsis,breathing, and movement of the scope and instruments. Having atechnology to overcome this problem would help provide a stableoperative space, which is clinically desired in the operativeenvironment.

Another current problem includes a lack of an endoscopic technology forretracting the tissue dynamically, for example, through an adjustabletissue retraction structure allowing for a controlled degree ofexpansion or collapse of the structure, to further configure the workingspace as desired around the instruments and target tissue. Such controlcan effectively provide for a method of adjusting the retractor, as wellas tissue placement, in-and-around the working space. By increasing andreleasing the tension on the retractor, the amount of tissue to beplaced in the working space, for example, can be better-gauged andcontrolled during a procedure. Moreover, the tissue retraction and,particularly, traction-contra-traction can be facilitated to help createa desired dissecting plane or position the tissue more optimally duringan operation. Having a technology to overcome this problem would helpcreate an operative environment that is more desirable for tissuedissection, retraction, cutting and a removal of tissue.

Another current problem includes a lack of an endoscopic technology fororganizing the endoscope, instruments, and working space in a mannerthat can maximize the working space for the treatment. The largerworking space can improve the ability to manipulate the instruments andendoscope in a minimally-invasive manner from outside the body. Namely,one of skill would like to have a working space that has a point ofentry for the instruments that is as far as practical from the targettissue to provide additional flexibility in approaching and visualizingthe target tissue, perhaps providing more operating room for selecting atrajectory of the instruments toward the target tissue that is, forexample, at least substantially perpendicular to the plane of dissectionof the target tissue. Having a technology to overcome this problem wouldprovide the person of skill with a system and procedure that is moredesirable for a removal of tissue.

In view of at least the above, one of skill in the art of endoscopic,gastrointestinal surgical treatments would appreciate the technologytaught herein which provides one or more of (i) a minimally-invasiveexpansion of the intra-luminal working space; (ii) an affixing,particularly an affixing that includes a reconfiguring withoutstretching or reconfiguring with stretching, of both the target tissueand surrounding tissue to help provide a stable, operative space; (iii)a retracting of the tissue dynamically, allowing for a partial orcomplete expansion or collapse, to further configure the working spacebetween the instruments and the target tissue; and (iv) an organizationof the endoscope instruments, such as the retractor and tools tomaximize the working space and maneuverability, allowing for a maximumflexibility in approaching and visualizing the target tissue. It shouldbe appreciated that having such improvements would reduce the technicalcomplexity, and increase the efficacy and safety of, otherwise complexendoscopic operations. Moreover, doing so at a low cost, while using anaffordable system that is introduced in the subject atraumatically andin a manner that does not substantially disrupt the conventionalcolonoscopy workflow, would be seen by those of skill as a verysubstantial advancement in the field of endoscopic surgical procedures.

In endoscopic procedures, to enable non-traumatic advancement of thecatheter through the anatomy to the target site, sufficient flexibilityis necessary. However, sufficient stability is also necessary to limitflexing of the distal region of the catheter once at the target sitewhere the expanded working space is created. It would be advantageous toprovide a catheter that achieves an effective balance of these competingobjectives.

SUMMARY

The teachings provided herein are generally directed to improved methodsand devices for operatively treating gastrointestinal disordersendoscopically in a stable, yet dynamic operative environment, and in aminimally-invasive manner. The systems, for example, include anendoscopic surgical suite. The surgical suite can have areversibly-expandable retractor that expands to provide a stable,operative environment within a subject. The expansion can be asymmetricaround a stabilizer subsystem to maximize space for a tool and in someembodiments an endoscope to each be maneuvered independently tovisualize a target tissue and treat the target tissue from outside thepatient in a minimally invasive manner. Embodiments taught hereinprovide, among other improvements, an increase in distance between toolports and the target tissue to improve maneuverability and triangulationof the tools with respect to the target tissue, as well as a largerfield of view.

In some embodiments, floating channels are provided to increase theflexibility of the system as compared to the use of fixed channels. Thefloating channels receive flexible instrument guides which providechannels for working instruments. Alternatively, working instruments canbe inserted directly into the floating channels.

In accordance with one aspect of the present invention, a system forperforming minimally invasive procedures in a working space within abody lumen of a patient is provided comprising a flexible catheterconfigured to receive a working instrument therethrough, the flexiblecatheter having a proximal portion, a distal portion, and a workingspace expanding system positioned at the distal portion. The workingspace expanding system includes first and second flexible elementsmovable from a non-expanded insertion position to an expanded positionforming an expanded region to expand the working space within the body.The first and second flexible elements are connected to a couplingstructure at a distal region. An expandable stabilizing member ismovable axially with respect to the coupling structure to stabilize thedistal portion of the flexible catheter.

In some embodiments, a covering is positioned over the first and secondflexible elements, the covering having an opening to receive bodytissue.

In some embodiments, the stabilizing member is movable from a firstposition further from the coupling structure to a second position closerto the coupling structure. In some embodiments, in the second positionthe stabilizing member is positioned over the coupling structure; inother embodiments, in the second position the stabilizing member ispositioned adjacent a distal end of the coupling structure.

In some embodiments, the stabilizing member is an inflatable balloon,and can have in some embodiments a donut-shape to form a gap to receivethe coupling structure within the gap. In other embodiments, thestabilizing member includes a mesh-like structure. In other embodiments,the stabilizing member includes a stent-like structure.

In some embodiments, the stabilizing member is connected to a secondcatheter, the second catheter extending through a lumen in the flexiblecatheter.

The system can further include one or more flexible guides slidablypositioned within the flexible catheter, wherein a distal portion of theflexible guides is movable to angled positions within the expandedregion and the flexible guides are configured and dimensioned to receivean endoscopic working instrument therethrough.

In some embodiments, a bridge member extends transversely between thefirst and second flexible elements to increase stability.

In accordance with another aspect of the present invention, a system forperforming minimally invasive procedures in a working space within abody lumen of a patient is provided comprising a flexible catheterconfigured to receive a working instrument therethrough, the flexiblecatheter having a proximal portion, a distal portion, and a workingspace expanding system positioned at the distal portion. The workingspace expanding system includes first and second flexible elementsmovable from a non-expanded insertion position to an expanded positionforming an expanded region to expand the working space within the body.The first and second flexible elements are connected to a couplingstructure at a distal region. An expandable stabilizing member ispositioned over the coupling structure and movable from a non-expandedposition to an expanded position to stabilize the distal portion of theflexible catheter.

In some embodiments, the stabilizing member includes a mesh-likestructure. In other embodiments, the stabilizing member includes astent-like structure. In other embodiments, the stabilizing memberincludes an inflatable balloon.

In some embodiments, the stabilizing member is connected to a secondcatheter, the second catheter extending through a lumen in the flexiblecatheter.

In accordance with another aspect of the present disclosure, a systemfor performing minimally invasive procedures in a working space within abody lumen of a patient is provided comprising a flexible catheterconfigured to receive a working instrument therethrough, the flexiblecatheter having a proximal portion, a distal portion and a working spaceexpanding system positioned at the distal portion. The working spaceexpanding system includes first and second flexible elements movablefrom a non-expanded insertion position to an expanded position formingan expanded region to expand the working space within the body. Anexpandable stabilizing member is positioned at the distal portion of theflexible catheter. The first and second flexible elements are connectedto the stabilizing member, wherein the stabilizing member is expandableto expand from a low profile insertion position to an expanded positionto stabilize the distal portion of the flexible catheter.

In some embodiments, the stabilizing member is an inflatable balloon.The stabilizing member can be axially fixed about the coupling structureand can be inflatable to move from a deflated insertion position to aninflated stabilizing position. In some embodiments, the inflatableballoon includes a rigid element supported therein and the first andsecond flexible elements are connected to the rigid element.

In some embodiments, the first flexible element has a lumen extendingtherethrough communicating with the stabilizing member for transport offluid to inflate the stabilizing member.

In accordance with another aspect of the present disclosure, a methodfor performing a minimally invasive procedure in a body lumen of apatient is provided comprising: a) providing a flexible catheter havinga working space expanding system and an expandable stabilizing member;b) providing a flexible endoscope to visualize target tissue; c)advancing the flexible catheter within the body lumen adjacent targettissue to be treated; d) visualizing target tissue with the flexibleendoscope; e) expanding the working space expanding system from anon-expanded insertion position to an expanded position to increase theworking space within the body lumen; and f) either before or after step(e), expanding the stabilizing member.

In some embodiments, the method further includes the step of retractingthe stabilizing member closer to the working space expanding system. Thestep of retracting can occur prior to or after the step of expanding theworking space expanding system. The step of retracting can occur priorto or after expanding the stabilizing member.

In some embodiments, the step of expanding the stabilizing memberincludes the step of inflating the expandable member. In otherembodiments, the step of expanding the stabilizing member includes thestep of expanding a mechanical structure.

In some embodiments, the working space expanding system includes firstand second flexible elements, the first and second flexible elementsconnected at a distal end by a coupler. In some embodiments the step ofretracting the stabilizing member moves the stabilizing member to aposition overlying the coupler and in other embodiments the step ofretracting the stabilizing member moves the stabilizing member to aposition adjacent a distal end of the coupler.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates a system for operatively treating gastrointestinaldisorders endoscopically in a stable, yet dynamic operative environment,and in a minimally-invasive manner, according to some embodiments.

FIGS. 2A and 2B illustrate how a system as taught herein can bepositioned for treating a lesion in the ascending colon, according tosome alternate embodiments.

FIGS. 3A-3L illustrate how a system as taught herein can be used inremoving a lesion in a colon, according to some embodiments, the colonshown in a cutaway view to show the system in perspective, wherein FIG.3A illustrates the system being inserted into the colon and having asheath covering the retractor, FIG. 3B illustrates the retractor in thenon-expanded position, FIG. 3C illustrates the retractor in the expandedposition to create an asymmetric working space and further showing theendoscope in an articulated position, FIG. 3D is a view similar to FIG.3C showing two endoscopic instruments extending from respective toolchannels, FIG. 3E illustrates the tool channels and the endoscopicinstruments bent toward the target lesion, FIG. 3F illustrates thelesion being removed from the wall of the colon by the endoscopicinstruments, FIG. 3G illustrates the lesion removed from the wall of thecolon and positioned within the retractor, FIG. 3H illustratesendoscopic instruments extending from the tool channels and bent towardthe colon wall to repair the defect in the colon wall resulting fromremoval of the lesion, FIG. 3I illustrates placement of clamps to closethe tissue defect in the colon wall, FIG. 3J illustrates the retractorin the collapsed position to capture the lesion for removal from thecolon; FIG. 3K illustrates the retractor encapsulated within the sheathfor removal from the colon, and FIG. 3L illustrates the closed tissuedefect after completion of the surgical procedure.

FIGS. 4A-4E illustrate details of a system as taught herein, in side,axial, and oblique views of expanded and collapsed configurations, andincluding a stabilizer subsystem, according to some alternateembodiments, wherein FIG. 4A is a side view of the system with theretractor in the non-expanded (collapsed) position, FIG. 4B is an axialview of the system with the retractor in the non-expanded position, FIG.4C is an axial view of the system with the retractor in the expandedposition, FIG. 4D is a perspective view of the system in the position ofFIG. 4A, and FIG. 4E is a view similar to FIG. 4D showing the retractorin the expanded position.

FIGS. 5A-5D illustrate side and top views of a system as taught herein,having side views and top views of expanded and collapsedconfigurations, according to some alternate embodiments, wherein FIG. 5Ais a side view of the system with the retractor in the non-expanded(collapsed) position, FIG. 5B is a side view similar to FIG. 5A showingthe retractor in the expanded position; FIG. 5C is a top view of thesystem with the retractor in the non-expanded position of FIG. 5A, andFIG. 5D is a top view of the system with the retractor in the expandedposition of FIG. 5B.

FIGS. 6A-6D illustrate side views of a system as taught herein, havingside views and cross-sections of expanded and collapsed configurationsof the system, according to some other alternate embodiments, whereinFIG. 6A is a side view of the system with the retractor in anon-expanded (collapsed) position; FIG. 6B is a side view similar toFIG. 6A with a housing half removed to show internal components of thesystem, FIG. 6C is a side view similar to FIG. 6A showing the retractorin an expanded position, and FIG. 6D is a side view similar to FIG. 6Bshowing the retractor in the expanded position.

FIG. 7 illustrates a cutaway view of the distal end of the outer tube ofa system as taught herein, showing components of the expansion andcollapse of the retractor, according to some embodiments.

FIG. 8 illustrates the cutaway view of FIG. 7 , showing the distal endof the outer tube of a system as taught herein, in which components ofthe system can be floating in the outer tube to enhance flexibility forpositioning the system in a subject, according to some embodiments.

FIGS. 9A and 9B illustrate side views of working, and/or floating,channels that can be used to guide tools as taught herein, according tosome embodiments.

FIGS. 10A-10E illustrate an alternate embodiment of the system wherein aretractor sheath covers a retractor of a system as taught herein,according to some embodiments, wherein FIG. 10A is a top view of thesystem with the retractor in a non-expanded (collapsed) position, FIG.10B is a perspective view of the system in a non-expanded position, FIG.10C is a side view of the system with the retractor in a non-expandedposition, FIG. 10D is a top view of the system showing the retractor inan expanded position, and FIG. 10E is a side view of the system showingthe retractor in the expanded position.

FIG. 11 is a perspective view of an alternate embodiment of the systemshowing the catheter and two tool channels.

FIG. 12 is a perspective view of the catheter of FIG. 11 being insertedover the proximal end of the endoscope of FIG. 13 (prior to insertion ofthe endoscope into the colon), the retractor system shown in thecollapsed position.

FIG. 13 illustrates insertion of the endoscope through the colon.

FIG. 14 is a perspective view showing the catheter of FIG. 11 beingfurther advanced over the endoscope of FIG. 13 , the retractor systemshown in the collapsed position.

FIG. 15 is a perspective view showing the catheter fully advanced overthe endoscope to the desired position adjacent the target tissue, theretractor system shown in the collapsed (non-expandable) position.

FIG. 16 is a perspective view of the proximal end of the catheter ofFIG. 11 .

FIGS. 17A and 17B are side views in partial cross-section showingmovement of the actuator from a proximal position to a distal positionto advance the rigidifying structure to stiffen the retractor system.

FIG. 17C is a perspective view similar to FIG. 15 showing an alternateembodiment of the rigidifying structure.

FIG. 17D is a perspective view similar to FIG. 17C showing therigidifying structure of FIG. 17C advanced over the flexible element.

FIG. 18 is a perspective view showing the two tool channels (guides)adjacent the proximal end of the catheter of FIG. 11 for insertiontherethrough.

FIG. 19A is a perspective view illustrating the tool channels insertedinto the catheter of FIG. 11 and FIG. 19B is a perspective viewillustrating an alternative embodiment of the tool channels.

FIGS. 20A and 20B are side views in partial cross-section showingmovement of the actuator from a proximal position to a distal positionto move the retractor system to the expanded position.

FIG. 21A is a view similar to FIG. 15 showing the retractor system inthe expanded position and further illustrating the tool channels beingadvanced into the working space (chamber) created by the expansion ofthe retractor system.

FIG. 21B is a view similar to FIG. 21A illustrating an alternateembodiment wherein the tool channels are advanced from the catheterprior to expansion of the retractor system.

FIG. 22 is a view similar to FIG. 21A showing a first endoscopicinstrument (tool) advanced from a first tool channel.

FIG. 23 is a view similar to FIG. 22 showing a second endoscopicinstrument (tool) advanced from a second tool channel.

FIG. 24 is a view similar to FIG. 23 showing both endoscopic instrumentsfurther advanced from the tool channels.

FIG. 25 is a view similar to FIG. 24 showing the endoscopic instrumentsfurther advanced from the tool channels to dissect the lesion on thecolon wall.

FIG. 26 is a view similar to FIG. 25 showing the lesion which has beenremoved from the colon wall by the dissecting instrument placed withinthe retractor system.

FIG. 27 is a perspective view of the proximal end of the cathetershowing proximal movement of the actuator to return the retractor systemto the collapsed position for removal from the colon.

FIG. 28 is a view similar to FIG. 26 showing the retractor system in thecollapsed position.

FIG. 29 is a view similar to FIG. 28 showing the covering member closedto encapsulate the lesion for removal.

FIG. 30 is a front view of the system in the expanded position of theretractor system and showing two tool channels extending from thecatheter.

FIGS. 31A and 31B are cross-sectional views illustrating the switch forretaining the suture for closing the covering (bag).

FIG. 32 is a perspective view of the distal end of the outer tube(catheter) of an alternate embodiment of the system showing two floatingchannels therein.

FIG. 33 is a perspective view of a proximal portion of the system ofFIG. 32 .

FIG. 34 is a close up cutaway view showing one of the floating channelsof FIG. 32 .

FIG. 35A is a view similar to FIG. 34 showing an alternate embodiment ofthe floating channel.

FIG. 35B is a view similar to FIG. 35A showing the floating channeladvancing within the fixed distal tube.

FIG. 35C is a view similar to FIG. 35B showing movement of the floatingchannel beyond the fixed distal tube.

FIG. 36 is a front view of the system of FIGS. 32 and 33 shown withinthe colon.

FIGS. 37A and 37B are transverse cross-sectional views through the outertube showing radial movement of an intermediate portion of the floatingchannels within the lumen of the outer tube.

FIG. 38 is a cross-sectional view illustrating bending of the outer tubeand movement of the floating channels of FIGS. 35A-35C.

FIGS. 39A and 39B are side perspective views of the distal portion ofthe system of FIG. 38 showing the effect of bending of the outer tubeand movement of the floating channels, and the retractor system shown inthe non-expanded configuration.

FIG. 39C is a bottom perspective view of the retractor system of FIG.39A.

FIG. 40 is a longitudinal cross-sectional view of an alternateembodiment of the system with the retractor system shown in thecollapsed insertion position.

FIG. 41 is a bottom perspective view of the system of FIG. 40 with theretractor system shown in the non-expanded configuration.

FIG. 42 is a side perspective view of the system of FIG. 41 .

FIG. 43A is a bottom perspective view of another alternate embodiment ofthe system having two flexible elements and a balloon stabilizer, andshowing the balloon in the distal non-expanded position.

FIG. 43B is a perspective view of a distal portion of the system of FIG.43A showing the balloon in the proximal non-expanded position;

FIG. 43C is a perspective view of the distal portion of the system ofFIG. 43A showing the balloon in the proximal expanded position adjacentthe distal coupler and further showing the retractor system expandedwithin a patient's colon.

FIG. 43D is a view similar to FIG. 43B showing a cover over the flexibleelements.

FIG. 44A is a perspective view of another alternate embodiment of thesystem having a balloon stabilizer and showing a donut shaped balloon inthe distal non-expanded position.

FIG. 44B is a perspective view of a distal portion of the system of FIG.44A showing the balloon in the expanded position distal of the distalcoupler;

FIG. 44C is a perspective view similar to FIG. 44B showing the expandedballoon overlying the distal coupler.

FIG. 45A is a perspective view of the distal portion of anotherembodiment of the system showing the donut shaped balloon in thenon-expanded position overlying the distal coupler.

FIG. 45B is a perspective view similar to FIG. 45A showing the donutshaped balloon in the expanded position over the distal coupler.

FIG. 46A is a perspective view of the distal portion of anotheralternate embodiment of the system showing the mesh structure in thenon-expanded position within the catheter.

FIG. 46B is a perspective view similar to FIG. 46A showing the catheterin the proximal position.

FIG. 46C is a perspective view similar to FIG. 46B showing the meshstructure in the expanded position.

FIG. 47A is a perspective view of the distal portion of anotheralternate embodiment of the system showing the stent-like structure inthe non-expanded position within the catheter.

FIG. 47B is a perspective view of the system of FIG. 47A showing thecatheter in the proximal position within a patient's colon.

FIG. 47C is a perspective view similar to FIG. 47A showing the stentstructure in the expanded position, and further showing the retractorsystem expanded within a patient's colon.

FIG. 48 is a perspective view of a distal portion of another alternateembodiment having four flexible elements for symmetric expansion andshowing the balloon in the expanded position.

FIG. 49A is a perspective view of a distal portion of another alternateembodiment of the system showing the flexible elements attached directlyto the balloon and the balloon in the non-expanded position.

FIG. 49B is a view similar to FIG. 49A showing the balloon in theexpanded position.

DETAILED DESCRIPTION

The teachings provided herein are generally directed to improved methodsand devices for operatively treating gastrointestinal disordersendoscopically in a stable, yet dynamic operative environment, and in aminimally-invasive manner. The systems, for example, include anendoscopic surgical suite that is created by the systems disclosedherein. The surgical suite can have a reversibly-expandable retractorthat expands to provide a stable, operative environment within asubject. In some embodiments, the expansion can be asymmetric around astabilizer subsystem to maximize space for a tool and an endoscope toeach be maneuvered independently to visualize a target tissue and treatthe target tissue from outside the patient in a minimally invasivemanner. Embodiments taught herein can provide, among other improvements,an increase in distance between tool ports and the target tissue toenhance the independent maneuverability and triangulation of each of thetools with respect to the target tissue. This increase in distance canalso provide a way of obtaining a larger field of view. The systemstaught herein, for example, can (i) enable a working space to bedynamically configured around the target tissue in tortuous body lumensand orifices such as the gastrointestinal tract using controls fromoutside the body; (ii) provide a flexible, passageway for multiplesurgical tools and instruments, such as endoscope and graspers to bepassed from outside the body towards the target tissues; (iii) organizeand/or constrain tools in the working space; (iv) at least substantiallyimmobilize and/or stabilize the target tissue and surrounding tissue fora treatment; and/or (v) enable control over the geometry position, andorientation of the instruments such as the grasper in the working spacefrom outside the body.

In some embodiments disclosed herein, an articulating endoscope isinserted through a channel of the catheter; in other embodiments thesystem is backloaded over a flexible endoscope, such as a conventionalcolonoscope, then the endoscope is inserted to a position adjacent thetarget tissue and then the catheter is advanced over the flexibleendoscope so the reshaping (retractor) system (cage) is next to thetarget tissue.

In some embodiments disclosed herein, the endoscopic working instruments(tools) for treating the target tissue are inserted directly through arespective lumen or channel of the multi-lumen catheter. In theseembodiments where the instruments (tools) are inserted directly into thelumen of channel of the catheter, the working instruments can have acurve at a distal end which automatically assumes the curved positionwhen exposed from the catheter so it can curve toward the target tissue,or alternatively, the working instruments can have a mechanism activelycontrolled by the user to articulate/angle the distal tip. In otherembodiments, instead of the endoscopic working instruments (tools) beinginserted directly into the channel or lumen of the catheter, a flexibletube is inserted through the lumen or channel of the catheter and actsas a guide for the instrument. That is, the flexible tube is firstinserted into the lumen or channel of the catheter and then theendoscopic instrument is inserted through the respective flexible tube.The flexible tube can have a curve at a distal end which automaticallyassumes the curved position when exposed from the catheter so it cancurve toward the target tissue, or alternatively, the flexible tube canhave a mechanism actively controlled by the user to articulate/angle thedistal tip. In these embodiments utilizing the flexible tubes, thecurving and maneuverability of the flexible tubes controls thepositioning and orientation of the endoscopic instruments, and thereforethe endoscopic instruments need not be provided with a pre-curved tip orarticulating mechanisms.

In preferred embodiments, the systems disclosed herein include aretractor which creates an asymmetric working space within the bodylumen. More particularly, when working in a confined body lumen, such asthe colon, expansion of the lumen is limited because it is undesirableto over-expand which could stretch the lumen beyond its ability toreturn to its normal state or more dangerously could rupture the lumen.The asymmetric working spaces disclosed herein are designed toreconfigure or reshape the body lumen-transform the cylindrical spacewithin the body lumen to a non-cylindrical asymmetrical space (i.e.,changing the geometry) to shift the space around the target tissue tocreate more working space around the target tissue to provide bothvisual and mechanical improvements. Stated another way, in a cylindricalworking space, there is a lot of area of unused space while in thereshaping of the embodiments disclosed herein the space is moved orshifted to reduce the unused space and create a larger area for tissueaccess and treatment.

The terms “treat,” “treatment”, and “treating” used herein include, forexample, the therapeutic and/or prophylactic uses in the prevention of adisease or disorder, inhibition of a disease or disorder, and/oramelioration of symptoms of disease or disorder. The term “subject” and“patient” can be used interchangeably and refer to an animal such as amammal including, but not limited to, non-primates such as, for example,a cow, pig, horse, cat, dog, rat, and mouse; and, primates such as, forexample, a monkey or a human.

In some embodiments, the systems taught herein can include dynamicallyreconfigurable, asymmetric retractor structures on the distal end of aflexible and torque-able multi-channel shaft having a handle that allowsfor control over both the stiffness and geometry of the working spaceformed by the expansion of the retractor. In some embodiments, theretractor can include a stabilizer subsystem having 2-8, 3-5, 4-6, orany range therein, flexible retractor elements. In some embodiments, theretractor elements can be aligned at least substantially parallel toeach other when fully collapsed for positioning in the patient. In someembodiments, the retractor elements are aligned on planes that arewithin about 5-30 degrees, about 10-25 degrees, about 15-20 degrees,about 15 degrees, or any range therein, of each other. In someembodiments, the retractor elements form a frame that has a lengthranging from about 4-12 cm. 6-10 cm, 7-9 cm, 5-11 cm, or any rangetherein. In some embodiments, the frame is about 8 cm long. In someembodiments, the retractor elements form a frame that has a widthranging from about 1-5 cm. 2-4 cm, or any range therein. In someembodiments, the frame is about 3 cm wide. In some embodiments, theretractor elements form a frame that has a height ranging from about 1-5cm. 2-4 cm, or any range therein. In some embodiments, the frame isabout 3 cm high. One of skill will appreciate that there are a number ofsuitable materials that can be used to make the retractor elements forthe purposes set-forth herein. In some embodiments, the retractorelements can be made from NITINOL. In some embodiments, the retractorelement can comprise multifilament steel wires or polymer cords. Thepolymer materials can include polyetheretherketone (PEEK), nylon,polyester, polycarbonate, polyurethane, or polyethylene. The gauge ofthe retractor elements can vary, depending on material. In someembodiments, the retractor elements can comprise wires that range fromabout 0.020″-0.40″ in diameter. In some embodiments, the retractorelements are about 0.030″ in diameter.

The term “about” is used in the teachings herein to describe possiblevariations in amounts or ranges that can be used in embodiments. It canbe used in embodiments, for example, to include the exact amount orrange specified, as well as a variation of which that would not create asubstantial difference in function. A difference in function can beinsubstantial, for example, where it is less than 20% in someembodiments, less than 15% in other embodiments, less than 10% in yetother embodiments, or perhaps even less than 5% in yet otherembodiments. One of skill will appreciate that the percentage differencein function required for to be substantial will depend on the functionof the embodiment itself that is under comparison.

The methods, devices, and systems taught herein can be used forminimally-invasive procedures. A non-invasive procedure, in contrast,can be defined as a procedure that includes no violation of the skin orthe mucosa, and no appreciable damage to any other tissues of the body.A minimally-invasive surgical operation, on the other hand, involvesminimal access trauma and minimal collateral tissue damage during asurgical operation. The terms “minimal,” “minimize,” “minimizing,”“minimized,” “avoid,” “avoiding,” “avoided,” can be used interchangeablyin some embodiments. Minimally-invasive surgery is desirable, forexample, to reduce trauma to the patient, speed the healing process,reduce risk and, thus, reduce the length and expense of a hospital stayby minimizing or avoiding tissue damage, or risk of tissue damage.Tissue damage, or the risk thereof, can be minimized or avoided, forexample, where a procedure is designed to minimize or avoid unnecessarytissue contact that may otherwise be associated with a procedure. Thegentle procedures taught herein, for example, are directed to preservingtissue during a gastrointestinal surgery.

The systems taught herein can be dynamic in some embodiments, forexample, such that the tissue retraction can include partial or completeexpansion or collapse of a retractor to facilitate an increase ordecrease in the distance between instruments and the target tissue,which is useful in reconfiguring the work space and aiding in axialmovements of the tools. By increasing and releasing the tension, theamount of tissue to be placed in the working space can also bebetter-gauged during a procedure, for example, and tissuetraction-contra-traction can be facilitated to help in creating adissecting plane during a removal of tissue. One of skill willappreciate having the ability to dynamically reconfigure the workingspace and optimize traction-contratraction on the target tissue, as thiscan facilitate surgical manipulations.

The systems disclosed herein also enable triangulation to be achieved.Tissue triangulation, wherein the tissue is triangulated between twoendoscopic instruments, enhances access and maneuverability.

FIG. 1 illustrates a system for operatively treating gastrointestinaldisorders endoscopically in a stable, yet dynamic operative environment,and in a minimally-invasive manner, according to some embodiments. Thesystem 100 can include a multi-lumen-catheter retractor system for easeof positioning in a subject, and such systems can be designed to providea minimally invasive treatment of the subject. The system 100 can have aflexible outer tube 105 configured for guiding one or more channels 110and an endoscope 115 within the system 100. The flexible outer tube 105can have a lumen (not shown), a proximal end (not shown), and a distalend 108 to house, for example, the channel(s) and the endoscope duringuse of the system 100. The lumen can extend from the proximal to thedistal end so the tool channels 110 can be manipulated at a proximal endby the user. The outer tube 105 can alternatively be a multi-luminaltube, so a separate lumen accommodates the endoscope and the individualtool channels, and during the use of the system 100, the channel 110 canserve as a guide through which a tool 120,125 can be inserted andmanipulated in a treatment of a target tissue 190 in thegastrointestinal tract 195 (or other areas) of the subject. The channel110 can, for example, be in operable contact with an independentlymanipulable-and-articulable tool, the channel having an elevatorcomponent for moving a bendable section. Thus, the length of the channelin some embodiments is sufficient so it can extend out the proximal endof the outer tube 105 for manipulation by the user. The tool channelsare bendable or articulable at a distal end so they angle away from thelongitudinal axis and toward the target tissue 190. Such bendability canbe achieved by providing tool channels (guides) 110 of shape memorymaterial with a shape memorized bent position as shown in FIG. 1 . Whencontained within the lumen of the outer tube 105 for insertion, the toolchannels 110 would have a substantially straightened position, and whenadvanced from the distal end of the outer tube 105, would return to thebent position of FIG. 1 . Other materials could also be utilized. Inalternate embodiments, the tool channel 110 can have a mechanism such asan elevator component or a control wire attached to a distal end whichcan be pulled by the user or pulled by an actuator to move the toolchannel to the bent position. These different ways to achievebendability (articulation) of the tool channels can be used for thevarious embodiments of the systems described herein.

In some embodiments, the tool inserted through the tool channel can beany tool known to one of skill. For example, the tool 120,125 caninclude a grasper, a forceps, a snare, a scissor, a knife, a dissector,a clamp, an endoscopic stapler, a tissue loop, a clip applier, asuture-delivering instrument, or an energy-based tissue coagulator orcutter. The bendability of the channel 110 for moving a bendablesection, often a distal end of the channel 110, manipulates, i.e.,bends, the tool 120,125 positioned therein. In some embodiments, atleast one channel 110 and/or the endoscope 115 can have at leastsubstantial freedom to move within the outer tube 105 during operation,or “float,” such that the system 100 can be considered to be a floating,multi-lumen-catheter retractor system. It should be appreciated that theterms “tool” and “instrument” can be used interchangeably in someembodiments taught herein. As can be appreciated, the tool 120,125 canbe flexible, at least at a distal end such that when the tool channel110 bends in a manner described above, it also bends the tool which ispositioned therein. Alternatively, it is also contemplated that the tool120,125 can be articulable or controllably bendable or composed of shapememory or other material so it bends without reliance on the bendabilityof the tool channels 110.

Although two tool channels 110 are illustrated, it should also beappreciated that a system with more than two tool channels or with onlyone tool channel can also be utilized. Additionally, the endoscope canhave a working channel for insertion of a working instrument such as agrasper or dissector.

It is also contemplated that the tools can be provided with bendabilitycharacteristics so that they can be inserted directly through the lumenof the outer tube 105 without the need for tool channels. In theseembodiments, the tools themselves have the bendable or articulablefeature so as not to rely on the tool channels for bending/anglingtoward the target tissue.

In some embodiments, the system can comprise a stable, yet dynamicoperative environment in that it can include a reversibly-expandableretractor 150, as shown in FIG. 1 , that expands to form a treatmentspace or working chamber 160 in the subject. The retractor 150 can beconfigured, for example, for the expansion to occur distal to the distalend 108 of the outer tube 105. In some embodiments, the retractor can atleast substantially render the target tissue 190 aperistaltic for thetreatment. The retractor 150 can have a variety of configurations toserve, for example, as a scaffolding within the gastrointestinal tract195. For example, the retractor 150 can include retractor elements151,152,153,154, along with a proximal coupler 198 operably connected tothe retractor elements 151,152,153,154, whether at least substantiallyattached and/or at least slidably-engaged to the retractor elements151,152,153,154, and a distal nexus or hub (or coupler) 199 for a distalpoint of an operable connection with the retractor elements151,152,153,154.

In the embodiment of FIG. 1 , retractor element 151 is a flexibleelement having a proximal portion 151 a extending from the proximalcoupler 198 at a first angle, a distal portion 151 b extending from thedistal hub or coupler 199 at a second angle preferably different fromthe first angle, and an engaging portion 151 c, which engages thetissue, extending between the proximal and distal portions 151 a, 151 b.As shown, portion 151 a extends at a greater angle to the longitudinalaxis than distal portion 151 c providing an asymmetric expansion of theretractor element itself. Thus, the length of the distal portion 151 bexceeds the length of proximal portion 151 a. Retractor element 152 canbe similarly configured and angled as retractor element 151, oralternatively of a different configuration and angle. Retractor elements151 and/or 152 can alternatively be configured so the proximal anddistal portions are of the same length and angles. Note the retractorelements 151, 152 expand in a direction to one side of the longitudinalaxis. This asymmetric expansion creates an asymmetric chamber describedbelow.

The retractor 150 can be a reversibly-stabilized andreversibly-expandable retractor, the retractor 150 forming anasymmetrical treatment space 160 upon the expansion. And, the retractor150 can be configured to reversibly stiffen an otherwise flexiblearrangement of the retractor 150, the arrangement designed to facilitateease of positioning of the system 100 in the subject and to reversiblystiffen for the expansion of the retractor 150. The stabilization of theretractor 150 can, in some embodiments, include a stabilizer subsystemfor stabilizing the retractor 150 as taught herein, the stabilizerhaving, for example, an at least substantially-rigid beam 175 to supportthe expanded retractor 150.

Rigidifying the retractor systems as disclosed in the variousembodiments herein, i.e., by utilizing a substantially rigid beam,advantageously stabilizes the retractor system, i.e., limits bending ofthe distal tip which could otherwise occur due to the opposing force ofthe tissue during expansion. Thus, the stabilizer carries the load andworks to create a more stabilized chamber. In some embodiments, beam 175can be substantially rectangular in cross-section, substantiallycircular in cross-section or of other cross-sectional shapes. It can beprovided of a stiffer material than the retractor elements. In someembodiments, the beam can have a cross sectional dimension larger than across sectional dimension of the retractor element. As shown in FIG. 1 ,the beam 175 is at the base of the chamber formed by the retractorelements, with the retractor elements extending radially (laterally)away from the beam 175. The beam 175 can be formed by the more rigidelement exposed when the retractor elements are exposed from the outertube for expansion, or alternatively, can be advanced independently fromwithin the outer tube as in some of the embodiments described in moredetail below.

In some embodiments, the outer tube can have any dimensions believed tobe useful to one of skill for the purposes taught herein. For example,the outer tube can have an outer diameter ranging from about 3 mm toabout 30 mm, about 5 mm to about 25 mm, about 7 mm to about 22 mm, fromabout 9 mm to about 20 mm, from about 11 mm to about 18 mm, from about 8mm to about 15 mm, from about 10 mm to about 16 mm, or any range thereinin increments of 1 mm. The length of the outer tube can range, forexample, from about 30″ to about 72″, from about 31″ to about 36″, fromabout 28″ to about 80″, from about 32″ to about 40″, from about 34″ toabout 38″, or any range therein in increments of 1″.

The outer tube can be manufactured from any materials know to be usefulto one of skill for the purposes taught herein. For example, the outertube can comprise a polymer, or perhaps a polymer having an embeddedwire reinforcement. The wire reinforcement can be a mesh, a braid, ahelical coil or any combination thereof. The wire reinforcement caninclude any material believed by one of skill to be useful for thepurposes set-forth herein. For example, wire reinforcement can comprisea material having an elastic modulus that is about 1-3 orders ofmagnitude higher than the polymer tube. The wire material can comprise,for example, a stainless steel having a diameter ranging from about0.003″ to about 0.017″, about 0.005″ to about 0.015″, about 0.010″ toabout 0.012″, or any range therein in increments of about 0.001″. Thetube hardness, or durometer, can be any of that which one of skill willfind useful for the purposes set forth herein. For example, the hardnesscan range, for example, from about 50 Shore A to about 60 Shore A, about40 Shore A to about 80 Shore A, about 45 Shore A to about 70 Shore A, orany range therein in increments of 1 Shore A. One of skill willappreciate that the outer tube should be flexible, elastically bendable,but sufficiently stiff torsionally to transmit torque from the handle orproximal end of the system to the retractor or distal end of the system.

The outer tube can be connected to at a distal end to a ring, referredto herein as the proximal coupler in some embodiments, which can haveportals formed therein for retractor elements to slide through, as wellas a desired orientation and positioning of the channels for theendoscope and at least one tool, such that the retractor elements,endoscope, and at least one tool are organized relative to each other ina predetermined manner to achieve a particular function, such as anincrease in working space, a better view of a plane of dissection, orany other procedural variable deemed of interest to one of skill. Forexample, in the embodiment shown in FIG. 1 , the portals for theretractor elements are spaced radially outwardly from the portals forthe endoscope and the tool channels.

In some embodiments, the retractor structures taught herein forsubstantially immobilizing the lesion to the extent desired for thetreatment. For example, the current use of loops and a piece-mealremoval of flat or wide-based polyps, such as those having a base ofabout 1 cm or wider, may not provide clear surgical margins, whereas thesystems taught herein can, in some embodiments, immobilize or affix theentire circumference of the bowel wall around the treatment area andfacilitate the production of clear surgical margins. One of skill willappreciate having a working space that can be provided by the systemstaught herein, the working space being (i) at least substantiallynon-collapsible, (ii) at least substantially aperistaltic; and, (iii) atleast substantially affixed at a particular point in the abdominalcavity in relation to any fixed body point, like a hip, for example.This is a significant improvement over existing systems, as existingsystems have not addressed many existing problems including, forexample, bowel collapse that can result from an air leak from theworking space; peristalsis that is normal, even in a sedated patient;and, additional undesired bowel movements caused by the patient'sbreathing, movement of the scope or other instrument manipulation, orperhaps even by a surrounding peristalsis causing movement at atreatment area. Such problems are addressed by systems taught herein. Assuch, systems taught herein can offer a rigid, stable structure havingat least substantial resistance to a variety of moving forces in theabdomen that are typically present during a gastrointestinal endoscopicprocedure. One of skill will appreciate decreasing the effects of thesemoving forces on the working space to help reduce otherwise inherenttechnical complexities, limited efficacies, and decreased safety duringendoscopic procedures.

In addition to creating the working space with the above advantages, theworking space is formed to create a sufficient working distance for thetools for treatment, e.g., polyp dissection, to enhance maneuvering andmanipulating the individual tools, enabling tissue triangulation.Working space distance is also advantageously formed to enhancevisibility of the target tissue.

In some embodiments, the systems taught herein can be slidablypositioned over an endoscope during use. In these embodiments, theendoscope would first be inserted to a position adjacent the targettissue and then the multi-lumen tube or catheter advanced over theendoscope, with the endoscope sliding over the endoscope receiving lumen(channel) of the outer tube or catheter. In fact, it should beappreciated that there are a variety of methods of using systems taughtherein that are already used by one of skill in current state-of-the-artprocedures. For example, the method can include inserting themulti-luminal tube into an overtube, cover, or sheath. And, in someembodiments, the endoscope can be a colonoscope. In many embodiments,regardless of the method of use, the retractor structures canmechanically retract one side of the colonic wall in an asymmetricmanner to increase the distance between the target lesion and theopposite wall, as well as between the lesion and the instruments intheir most retracted, but visualized, position to increase the effectivework space.

In some embodiments, the systems can include a multi-lumen catheterhaving at least 2 working channels for manipulating tools and anendoscope, each of the two working channels having 6 degrees of freedomthat are independent from each other and the endoscope. The ability toindependently manipulate the endoscope and tools allows, for example,one instrument to retract the tissue or lesion away or substantiallyperpendicular to another instrument, for example, the dissectinginstrument, while independently optimizing the endoscope's position and,hence, the view of the treatment area. This would facilitate the removalof tissue with clear margins. The channels can manipulate the tools withseveral degrees of freedom, 6 degrees of freedom in some embodiments,providing a greatly enhanced maneuverability in the working area whencompared to current state-of-the-art systems. In some embodiments, theat least one independently manipulable-and-articulable tool can beindependently rotatable to an angle of up to about 360 degrees, about315 degrees, about 270, about 225 degrees, about 180 degrees, about 135degrees, or about 90 degrees in the working area. In addition the toolscan be independently bendable to an angle of up to about 180 degrees,about 135 degrees, about 90 degrees, or about 45 degrees in at least onedirection in the working area.

The systems taught herein can provide for organizing the orientation ofthe floating channels, in order to further facilitate improving theflexibility of the system. In some embodiments, for example, theproximal coupler, the ring that can be attached to the distal end of theouter tube, can be used to organize the tools and endoscope in aparticular arrangement to facilitate a particular positioning of thetools as they emerge from the shaft into the working space created bythe retractor. In some embodiments, the tool channels can be placedfurther than the endoscope from the retractor elements that expand themost. Likewise, the proximal end of the outer tube can also haverespective openings for each of the channels, and these openings can be,for example, a part of a handle coupler, or the handle itself, operablyconnecting one or more of the channels to the outer tube. The operableconnection between the outer tube and channels can provide forcontrolling the endoscope and tools, for example, from outside thepatient. The rings can be made of any material believed by one of skillto be suitable for the purposes discussed herein. For example, the ringscan be made of stainless steel, or perhaps a plastic such aspolycarbonate or acrylonitrile butadiene styrene (ABS).

It should be appreciated that, in some embodiments, the systems taughtherein can include any combination of components, the selectedcombination of which is designed to be operable with components that areobtained separate from the system. For example, the system can includean outer tube and a retractor component, the outer tube being operablewith at least one channel obtained separately and an endoscope obtainedseparately. Likewise, the system can include an outer tube, a retractor,and an endoscope, and the channels are obtained separately; or an outertube, a retractor, and a channel, the endoscope obtained separately.Moreover, the system can include an outer tube, a retractor, anendoscope, and at least one channel; or, a handle, an outer tube, aretractor, an endoscope, at least one channel, and at least one tool.

The terms “substantial,” and “substantially” can be used, for example,to refer to a relative measure for a parameter. It can be used in someembodiments, for example, to refer to a degree of change or functionthat relates to an amount, a performance, or some other characteristic.The following are for purposes of example in describing generalembodiments: As described, the systems can be considered to be floatingsystems, can have a floating channel, a floating endoscope, multiplefloating channels, or a combination thereof, in some embodiments. Forexample, the phrase, “an at least substantially floating arrangementwithin the system”, can refer to an arrangement, for example a channelor endoscope arrangement, that can have some attachment that restrictsmovement in at least one direction, a minimal attachment to minimizesuch restriction of movement, or perhaps no attachment at all, toanother system component. For example, a channel or endoscope can bearranged to be at least substantially floating in the outer tuberelative to a second such system that does not use a floating-typearrangement to increase flexibility, or inherently achieve an increasein flexibility, of the second such system. As such, in many embodiments,the endoscope and/or channel can have a substantial portion of itsarrangement unattached within the system, allowing the substantialportion to “float” or move substantially freely within the outer tube.The “substantial portion” can be, for example, a percentage of thearrangement that must remain unattached within the system to provide aperformance characteristic, such as an increased flexibility of thesystem when compared to the second such system that does not use afloating-type arrangement to increase flexibility, or inherently achievean increase in flexibility, of the second such system.

The phrase, “at least substantially render the target tissueaperistaltic for the treatment”, for example, can refer to the targettissue having some minimal peristalsis, or perhaps no peristalsis, underthe conditions of normal use to provide a performance characteristic,such as controlling movement of the target tissue to facilitatetreatment. The phrase, “at least substantially attached”, for example,“at least substantially attached to the lumen of the outer tube”, forexample, can refer to a component having a fixed attachment or moveableattachment. In some embodiments, the attachment can be between thecomponent and the lumen, such that there is a loss of at least onedegree of freedom of movement of the component. For example, thecomponent can slide and/or rotate in relation to the lumen of the outertube, as long as the sliding and/or rotating occur in relation to aparticular fixed point on the lumen. Likewise, “at least substantiallyattached” can, of course, mean “fixed”, “reversibly fixed,” or the like,in some embodiments. Likewise, “at least slidably-attached” can refer toan attachment between components that allows for at least sliding motionbetween components such as, for example, a sliding motion between a portand a tube. In some embodiments, an endoscope can be at leastslidably-attached, for example, where the scope is allowed to slide inthe direction of the scope's central axis in and out of a port, suchthat the distance that the scope extends beyond the port is adjustable.And, in some embodiments, a component can be “at leastslidably-attached” where it can slide as well as move in otherdirections. For example, the port can be substantially larger than thescope, in some embodiments, such that the scope can slide axially, aswell as move side-to-side, align its central axis parallel to thecentral axis of the outer tube, or perhaps, misalign its central axis tonot be parallel to the central axis of the outer tube.

The phrase, “at least substantially increases the flexibility” can referto an orientation of components that enhances the flexibility of asystem when compared to another orientation and design of thecomponents. For example the phrase “at least substantially increases theflexibility of the system over a second such system” can refer to acomparison of flexibility of the claimed system over the second systemnot having the floating arrangement under the conditions of normal use,such that the flexibility of the system has increased to a minimalamount that improves the ease of positioning the system in the subjectfor the treatment of the target tissue.

The phrase, “at least substantially rigid component,” can refer to acomponent that is rigid, or sufficiently rigid, such that the desiredfunction is obtained, under the forces that are created with normal use.For example, a desired function may be to prevent or inhibit theoccurrence of a bending moment of the rigid component at one or morepoints along the length of a retractor upon expansion of the retractorin the subject. In some embodiments, the systems taught herein can havea retractor with four retractor elements, at least two of which areexpandable in the subject to create a working space for a treatment. Inthis example, the expansion of the at least two retractor elementstoward the target tissue to create the working space requires a forcesufficient to retract the tissue and, creates an opposing force in theopposite direction that can create the bending moment in the rigidcomponent. One of skill should appreciate that such a bending moment canbe problematic, for example, where it contributes to an instability thataffects the user's control over the position of the retractor during atreatment of the target tissue. In such embodiments, a component thatprevents or inhibits the bending moment can be “at least substantiallyrigid,” for example, where the user retains a desired level of control,or at least sufficient control, over the position of the retractorduring the retraction of the target tissue. In some embodiments, acomponent that prevents or inhibits a bending moment, whether in or outof the subject, can be at least substantially rigid where the bending ofthe component due to the expansion of the retractor creates a deflectionthat ranges from 0.0 to about 5 degrees, about 1.0 degree to about 10degrees, about 2.0 degrees to about 12 degrees, about 3.0 degree toabout 10 degrees, about 1.0 degree to about 15 degrees, about 1.0 degreeto about 9.0 degrees, about 1.0 degree to about 8.0 degrees, about 1.0degree to about 7.0 degrees, about 1.0 degree to about 6.0 degrees,about 1.0 degree to about 5.0 degrees, about 1.0 degree to about 4.0degrees, or any range therein in increments of about 0.1 degree. In someembodiments, the deflection of the rigid component cannot exceed about1.0 degree, about 2.0 degrees, about 3.0 degrees, about 4.0 degrees,about 5.0 degrees, about 6.0 degrees, about 7.0 degrees, about 8.0degrees, about 9.0 degrees, about 10.0 degrees, or any 0.1 degreeincrement therein. The bending can be measured, for example, as a pointof deflection from the original position of the rigid component's axisfrom force created on the rigid component through the expansion.

The terms “substantial” or “substantially” can be used interchangeablyin some embodiments, and can be described using any relative measuresacceptable by one of skill. For example, relative percentages can beused to indicate a substantial amount, substantial change, substantialdifference, substantial function, or the like. In some embodiments, thepercentage can be greater than 10%, greater than 20%, greater than 30%,greater than 40%, or greater than 50%. In some embodiments, thepercentage can be greater than 60%, greater than 70%, or greater than80%. And, in some embodiments, the percentage can be greater than 90%,greater than 95%, or in some embodiments, even greater than 99%. Forexample, a substantial [amount]” or a “substantial [change]”, caninclude any amount or change relative to a reference parameter. Theamount or change, for example, can include an increase or decreaserelative to the reference parameter, can be compared to a referencepoint for the parameter. The deviation from the reference point can be,for example, in an amount of at least 1%, at least 2%, at least 3%, atleast 5%, at least 10%, at least 15%, at least 20%, at least 25%, atleast 30%, at least 35%, at least 40%, at least 45%, or any 1% incrementtherein. Also, for example, a “substantial [function]” or “substantially[functioning]” limitation can serve as a comparison to a referencefunction parameter, to indicate a deviation that will still provide theintended function. Reference functions can include, for example,floating, aperistalsis, attaching, flexing, rigidity, a position orpositioning relative to another object, and the like. The deviation fromthe reference point can be, for example, in an amount of less than 1%,less than 3%, less than 5%, less than 10%, less than 15%, less than 20%,less than 25%, less than 30%, less than 35%, less than 40%, less than45%, or any 0.1% increment therein. For example, a component can have anacceptable, substantial [function] when it deviates from the referenceby less than the acceptable deviation.

As such, the system can include a floating, multi-lumen-catheterretractor system for ease of positioning in a subject, and such systemscan be designed to provide a minimally invasive treatment of thesubject. In some embodiments, the systems comprise a highly flexibleouter tube configured for guiding a floating channel and/or a floatingendoscope in an at least substantially floating arrangement within thesystem. This flexible outer tube can have a lumen, a proximal end, and adistal end. And, during a use of the system, the floating channel canserve as a guide through which a tool is manipulated in a treatment of atarget tissue in a subject. In some embodiments, the tool can include agrasper, a forceps, a scissor, a knife, a dissector, an endoscopicstapler, a tissue loop, a clip applier, a suture-delivering instrument,or an energy-based tissue coagulator or cutter. And, in someembodiments, the floating channel can have an elevator component formoving a bendable section to manipulate the tool. In some embodiments,at least one channel and/or the endoscope can have at least substantialfreedom to move within the outer tube during operation, or “float,” suchthat the system can be considered to be a floating, multi-lumen-catheterretractor system as taught herein.

Likewise, the system can also comprise a stable, yet dynamic operativeenvironment in that it can include a reversibly-expandable retractor(working space expanding system) that expands to form a treatment spacein the subject. The retractor can be configured, for example, for theexpansion to occur distal to the distal end of the outer tube and atleast substantially render the target tissue aperistaltic for thetreatment; wherein, during a use of the system in a subject, thefloating channel can be at least substantially attached to the lumen ofthe outer tube at a first proximal location and a first distal location,and be at least substantially floating in the lumen of the outer tubebetween the first proximal location and the first distal location.Likewise, during the use of the system, the floating endoscope can be atleast slidably-attached to the lumen of the outer tube at a secondproximal location and a second distal location, and be at leastsubstantially floating in the lumen of the outer tube between the secondproximal location and second distal location. And, during the use of thesystem, the at least substantially floating arrangement can at leastsubstantially increase the flexibility of the system over a second suchsystem, the second such system having a lumen for a tool and anendoscope affixed to the lumen throughout the length of the outer tubebetween the proximal end and the distal end of the outer tube. Theincreased flexibility of the at least substantially floating arrangementcan facilitate an ease of positioning the system in the subject for thetreatment of the target tissue. Moreover, the retractor can be areversibly-stabilized and reversibly-expandable retractor, the retractorforming an asymmetrical treatment space upon the expansion. And, theretractor can be configured to reversibly stiffen an otherwise flexiblearrangement of the retractor, the flexible arrangement designed tofacilitate the ease of positioning of the system in the subject and toreversibly stiffen for the expansion of the retractor.

FIGS. 2A and 2B illustrate how a system as taught herein can bepositioned for treating a lesion in the ascending colon, according tosome embodiments. It should be appreciated that any series of steps andmethods known to one of skill to be useful in the positioning 200 can beused with systems taught herein. FIG. 2A illustrates how an endoscope215 can be used to locate the lesion, a target tissue 290 in a portionof the ascending colon 295. FIG. 2B illustrates how themulti-lumen-catheter retractor system 201 can be guided to the targettissue 290 using the endoscope 215 as a guide for the positioning 200 ofthe system in the treatment of the target tissue 290. As can beappreciated, the multi-lumen catheter is advanced over the endoscope 215as shown in FIG. 2B.

FIGS. 3A-3L illustrate how a system as taught herein can be used inremoving a lesion in a colon, according to some embodiments. As notedabove, the system can also be used in other areas of the patient's bodyand to treat other target tissue. The description herein regardingremoval of a polyp from the wall of the colon is shown and described byway of example as the system (as well as the other systems disclosedherein) can be used for other surgical applications and in other bodyspaces. The system can be positioned as in FIGS. 2A and 2B in thetreatment 300 of a gastrointestinal lesion 390, and a multidirectionaland multi-angular approach to the lesion can be used. As in FIGS. 2A and2B, for example, the approach can include identifying a lesion in agastrointestinal lumen of a subject using an endoscope 315; and, forminga substantially rigid and stable endoluminal working area for treating atarget tissue, the gastrointestinal lesion 390. In FIG. 3A, the systemis positioned at the lesion 390, and in FIG. 3B, the expandableretractor 350 is exposed for subsequent expansion to create anasymmetrical working space 360 (FIG. 3C). In FIG. 3A, a sheath or cover355 is positioned over the retractor elements to facilitate insertion,with the distal end of the sheath 355 abutting the distal coupler 399 oralternatively overlying the distal coupler. After insertion to thetarget site, the sheath (or outer tube) 355 is removed to expose theretractor elements for subsequent expansion as shown in FIG. 3B. Itshould also be appreciated that, alternatively, the retractor elementscan be biased to an expanded position and retained in a collapseddelivery position by the sheath 355. In such embodiments, removal of thesheath 355 to expose the retractor elements would enable the retractorelements to automatically expand to their expanded position of FIG. 3C.

FIGS. 3C and 3D illustrate the creation of the working space 360 withinthe body lumen, and manipulation of the endoscope 315 and tools 320,325.After positioning the retractor 350 in proximity to the lesion 390, theretractor 350 is expanded to form the asymmetrical working space 360 forthe treating of the lesion 390. The retractor 350 in some embodimentscan be expanded by moving distal coupler 399 and proximal coupler 398relative to one another, wherein as the distance between the couplers399, 398, shortens, the retractor elements are forced more laterallywith respect to the longitudinal axis of the outer tube (catheter) 305.In alternate embodiments, the retractor elements can be operablyconnected to an actuator such that the actuator is moved to bow theretractor elements such as in the embodiment of FIG. 11 discussed indetail below. In still other alternative embodiments, the retractorelements can be composed of a shape memory or other material such thatwhen exposed from the outer tube or sheath, they automatically return totheir expanded configuration, e.g., their shape memorized expandedconfiguration. When such shape memorized retractor elements areutilized, once exposed they would automatically move from the positionof FIG. 3B to the position of FIG. 3C.

The system can have any configuration taught herein, such as (i) atleast one independently manipulable-and-articulable scope 315 to be usedin viewing the lesion 390, (ii) at least one tool channel 310 for atleast one independently manipulable-and-articulable tool 320,325 to beused in the treating of the lesion 390, and (iii) the retractor 350,which can be an asymmetrically expandable structure. In someembodiments, the retractor 350 can be expanded asymmetrically toward thelesion 390, the expanding including a portion of the retractor 350pushing on tissue surrounding the lesion 390 to increase the workingarea (space) within the body space (lumen) by providing an asymmetricalworking area and thus facilitate an entry of the lesion 390 into theworking area 360 for the treating. The retractor 350 can be locateddistal to the distal end of the outer tube 305 and the asymmetricalworking area 360 can be substantially rigid and stable relative to theindependently manipulable-and-articulable scope 315 and the at least onetool 320,325 to facilitate treating the lesion 390. The treating of thelesion 390 can include, for example, (i) viewing the lesion 390 with thearticulating scope 315 and (ii) using the at least one tool 320,325 inthe treatment of the lesion 390 with a multidirectional andmulti-angular approach to the lesion 390 in the asymmetrical workingarea 360.

In the embodiment of FIGS. 3A-3J, four retractor elements are provided.Two retractor elements 353, 354 are at the base of the retractor systemand can have an outwardly bowed or arcuate shape, or alternatively, asubstantially straight shape, or have accurate and substantiallystraight portions. Two retractor elements 351, 352 expand more radiallyoutwardly to apply a force against the wall of the colon on which thelesion is found. These retractor elements are described in more detailbelow.

In some embodiments, the independently manipulable-and-articulable scope315 and the at least one tool 320,325 can be independently movableaxially in the working area 360, independently rotatable in the workingarea 360, and independently bendable in at least one direction in theworking area 360. Accordingly, in some embodiments, the portion of theretractor 350 pushing on the tissue surrounding the lesion 390, e.g.retractor elements 351, 352, can be expanded further from the centralaxis 307 of the distal end of the outer tube 305 than other portions ofthe retractor to provide an even larger working area 360 for thetreating of the lesion 390 when compared to a second such structure thatmerely expands symmetrically around the central axis 307 of the distalend of the outer tube 305. This is due to the fact that it is desirableto create the largest working distance from the instrument tips to thetarget tissue, achieved by changing the configuration, i.e., reshaping,of the colon in the target area, but without overstretching, damaging orrupturing the colon.

Note that after the retractor system is expanded as shown in FIG. 3C,the endoscope 315 can be articulated in the working space 360 toward thetarget lesion 390 to improve visibility.

FIG. 3E illustrates a multidirectional and multi-angular approach to thelesion 390, showing the step of positioning the work area 360, endoscope315, and tools 320,325 in relation to the lesion 390. After theretractor 350 is expanded as shown in FIG. 3C, the user of the systemcan view and approach the lesion 390 with the tools 320,325 from nearlyany desired angle within the working space 360. The tool channels 310are advanced through the respective lumens in the multi-lumen catheteror tube and the endoscopic tools or instruments are inserted through thetool channels 310, with the distal ends of the tools extending distallyof the tool channel 310 as shown in FIG. 3D. The advantages of the toolchannels are described below in more detail in conjunction with theembodiment of FIG. 11 , and such advantages are applicable to this andother embodiments utilizing the tool channels. As noted above, it isalso contemplated that in alternative embodiments, the endoscopic toolscan be inserted directly into the lumens of the catheter or tube,without the use of tool channels, provided they have thebending/articulating characteristics described above which enable theirmanipulation without the use of bendable/articulatable tool channels.

FIG. 3F illustrates the versatility of the system, showing the step ofremoving the lesion 390 using tool 320 to excise the lesion 390 from anindependently chosen first angle, while tool 325 can be used to graspthe lesion 390 from an independently chosen second angle and endoscope315 can be used to view the lesion 390 from an independently chosenthird angle. As shown, the different angling of the tools 320 325advantageously achieve tissue triangulation to facilitate access,maneuverability and removal of the lesion. After the excision of thelesion 390 from the gastrointestinal tract 395 by the dissection tool320, a tissue defect 397 remains. Note the dissection tool 320 can insome embodiments be in the form of an electrosurgical instrument,although other dissecting/excising tools can also be utilized. FIG. 3Gillustrates the step of releasing the excised lesion 390 into theretractor assembly in preparation for completion of the procedure. FIGS.3H and 3I illustrate the step of closing the tissue defect 397, showingthat tool 320 for excision of the lesion 390 has been replaced by tool322 for closure of the lesion. The lesion can be closed by variousmethods such as mechanical (e.g., clips staples or structures), glue,electrosurgical energy, etc. FIGS. 3J and 3K illustrate the steps ofcapturing the lesion 390 for removal using tool 323 and collapsing theretractor 350 to capture and contain the lesion 390 within the collapsedretractor elements 351, 352, 353, 354 in preparation for removal of thesystem from the subject, including the use of an optional retractorcover 355 or other sheath or sleeve which can be slid over the catheterto further encapsulate the lesion retained within the collapsedretractor elements. FIG. 3L is a view of the closed tissue defectfollowing completion of the treatment.

In some embodiments, as shown for example in FIGS. 3B-3J, the system cancomprise a stable, yet dynamic operative environment in that it caninclude a reversibly-expandable retractor 350 that expands to form atreatment space 360 in the subject. The retractor 350 can be configured,for example, for the expansion to occur distal to the distal end 308 ofthe outer tube (catheter) 305. In some embodiments, the retractor can atleast substantially render the target tissue 390 aperistaltic for thetreatment. The retractor 350 can have a variety of configurations toserve, for example, as a scaffolding within the gastrointestinal tract395. For example, the retractor 350 can include retractor elements351,352,353,354, along with a proximal coupler or hub 398 operablyconnected to the retractor elements 351,352,353,354, whether at leastsubstantially attached and/or at least slidably-engaged to the retractorelements 351,352,353,354, and a distal nexus or coupler 399 for a distalpoint of an operable connection with the retractor elements351,352,353,354. The distal nexus or hub 399 is shown in the shape of aring, although it can be virtually any shape desirable to one of skill,such as a cone, hemisphere, sphere, and the like, and it may or may notinclude a port for passage of the endoscope beyond the distal end of thesystem. As noted above, in some embodiments, the proximal coupler 398can be moved toward the distal coupler 399, the distal coupler movedtoward the proximal coupler 398, or both couplers moved toward eachother to reduce their distance to force the retractor elements radiallyoutwardly. The extent of outward expansion of the retractor elements canbe controlled by controlling the distance between the proximal anddistal couplers 398, 399, The retractor can be repeatedly moved betweenexpanded and retracted positions as desired by adjusting the distancebetween the coupler 398, 399. Such controlled expansion of the retractorelements can also be achieved by operatively coupling the proximal endof the retractor elements to an actuator as in the embodiment of FIG. 11. Alternatively, as noted above, the retractor elements can be composedof a material, e.g., shape memory material, to automatically expand whenexposed from a catheter or sheath.

In the expanded position of the retractor elements as shown, retractorelement 351 is a flexible element having a proximal portion 351 aextending from the proximal coupler 398 at a first angle, a distalportion 351 b extending from the distal hub or coupler 399 preferably ata second angle different from the first angle, and an engaging portion351 c, which engages the tissue, extending between the proximal anddistal portions 351 a, 351 b. As shown, portion 351 a extends at agreater angle to the longitudinal axis than distal portion 351 bproviding an asymmetric expansion of the retractor element itself. Thus,the length of the distal portion 351 b exceeds the length of portion 351a. Retractor element 352 can be similarly configured and angled asretractor element 351, or alternatively of a different configuration andangle. Retractor elements 351 and/or 352 can alternatively be configuredso the proximal and distal portions are of the same length and angles.Note the retractor elements 351, 352 expand in a direction to one sideof the longitudinal axis. This asymmetric expansion creates anasymmetric chamber (working space). Retractor elements 351, 352 canextend in an arcuate or bowed manner or substantially straight manner asmentioned above. In some embodiments, the retractor elements 351, 352only expand in one direction with respect to the longitudinal axis ofthe catheter so they remain above (as viewed in the orientation of FIG.3D) a longitudinal plane containing the longitudinal axis. In someembodiments, only elements 351, 352 expand while elements 353, 354,which form the base of the retractor (cage) remain in substantially thesame position in the insertion (collapsed) and expanded position of theretractor. Note as with the retractor elements of FIG. 1 , the elements351, 352, 353, 354 can be covered with a plastic or other material tocreate a covered chamber as in the embodiment of FIG. 10A describedbelow.

The retractor 350 can be a reversibly-stabilized andreversibly-expandable retractor, the retractor 350 forming anasymmetrical treatment space 360 upon the expansion. And, the retractor350 can be configured to reversibly stiffen an otherwise flexiblearrangement of the retractor 350, the arrangement designed to facilitateease of positioning of the system 300 in the subject and to reversiblystiffen for the expansion of the retractor 350. The stabilization of theretractor 350 can, in some embodiments, include a stabilizer subsystemas taught herein, the stabilizer having, for example, an at leastsubstantially-rigid beam 375 to support the expanded retractor 350. Thesubstantially rigid beam 375 can be substantially rectangular incross-section, substantially circular in cross-section or of othercross-sectional shapes. It can be provided of the same or of a stiffermaterial than the retractor elements. It helps to create a morestabilized chamber as described herein. As shown, the beam 375 is at thebase of the chamber formed by the retractor elements, with the retractorelements extending radially (laterally) away from the beam 375. The beam375 can be formed by the more rigid element exposed when the retractorelements are exposed from the outer tube for expansion, oralternatively, can be advanced independently from the outer tube orformed by advancement of a rigidifying structure as in some of theembodiments described in more detail below.

FIGS. 4A-4E illustrate details of an alternate system as taught herein,in side, axial, and oblique views of expanded and collapsedconfigurations, and including a stabilizer subsystem, according to someembodiments. The figures illustrate an example of a multi-lumen cathetersystem which is similar to the system of FIGS. 3A-3K in that it has areversibly-stabilized and reversibly-expandable retractor for aminimally invasive treatment of a subject. FIGS. 4A-4C illustrate sideand axial views that show that the system 400 can comprise a flexibleouter tube (or catheter) 405 for guiding a tool channel (not shown) andan endoscope (not shown) within the system 400 in the same manner assystem 300. The flexible outer tube 405 has a lumen, a proximal end (notshown), and a distal end 408. The one or more tool channels (not shown)serves as a guide through which an endoscopic tool (not shown) can bemanipulated in a treatment of a target tissue in a subject in the samemanner as tool channels 310 of FIG. 3G manipulate tools 320, 325. Insome embodiments, the retractor 450 can be a reversibly-stabilized andreversibly-expandable retractor 450 forming a treatment space uponexpansion and configured for the expansion to occur distal to the distalend 408 of the outer tube 405. The retractor 450 can be designed toreversibly-stiffen an otherwise flexible arrangement of the retractor450, the flexible arrangement designed to facilitate the positioning ofthe system in the subject and to reversibly-stiffen for the expansion ofthe retractor 450. In these embodiments, the reversibly-stiffenedarrangement of the retractor 450 can form an at leastsubstantially-rigid beam 475 from an otherwise flexible beam 470 as astructural support for the expansion of the retractor 450. In someembodiments, the stabilizer subsystem can include the flexible beam 470,which may comprise a flexible tube, and a way for creating the at leastsubstantially-rigid beam 475. This, as taught herein, can include allembodiments taught herein, including the mechanisms forslidably-engaging an at least substantially-rigid rod or beam, forexample, within the flexible rod or beam 470 prior to expanding theretractor. In some embodiments, the terms “rod” and “beam” can be usedinterchangeably and, in some embodiments, the terms “beam” and “tube”can be used interchangeably. The beam 475 can be configured and functionin the same manner as described above for beam 375, including thealternatives described herein.

In some embodiments, the flexible beams taught herein in each of theembodiments disclosed can comprise a polymer, such as polyimide,polyether block amides (PEBAX), nylon, polyethylene, polyurethane,polyvinylchloride (PVC), PEEK, or polytetrafluoroethylene (TEFLON). Oneof skill will appreciate that the flexible beams can be reinforced tubesmade from components and designs known to the art. The flexible beam canbe, for example, a flexible tube that is reinforced with metal wires,braids, or coils that include, for example, a metal such as a stainlesssteel or NITINOL. In some embodiments, the flexible tube can be kinkresistant and transmit torque. And, in some embodiments, the flexibletube can comprise a combination of both flexible sections and rigidsections. In these embodiments, a flexible section can lie between rigidsections, for example. Such flexible tubes can include composites ofoverlapping tubes joined using any method known to one of skill,including bonding using epoxy or cyanoacrylates, in some embodiments.

In some embodiments, any of the systems taught herein can include abridge member to add stability to the retractor. For example, theretractor system 450 can include a bridge member 444 configured tomaintain a desired orientation of the retractor elements 451,452,453,454during the expansion, the bridge member 444 operably stabilizing atleast two 451,452 of the four retractor elements 451,452,453,454. Thatis, in the embodiment of FIG. 4A, the bridge member 444 is attached tothe two retractor elements 451, 452 which are configured to expandlaterally outwardly to expand or reconfigure the tissue wall. The bridgemember 444 creates a transverse structure for the elements 451,452,limiting side-to side movement. As shown, bridge member 444 can alsoinclude a second bridge section 444 a connected to bridge 444 and toretractor elements 452 and 453 thereby connecting all four retractorelements 451, 452, 453, 454. The upper surface (as viewed in theorientation of FIG. 4B) can be arcuate as shown. The bridge member 444can be a separate component or alternately integrally formed with oneboth of the retractor elements 451, 452. The bridge member can becomposed of a material similar to the elements 451, 452 or can becomposed of a different material.

Additional bridge members can be provided on the retractor elements 451,452 to increase stability. Note that one or more bridge members can beused with the other retractor embodiments disclosed herein. Note thatthe bridge member 444 can, in some embodiments, in the collapsedposition, angle radially outwardly from the longitudinal axis such as inFIGS. 4B and 4D, but change to angle more radially inwardly in theexpanded position of FIGS. 4C and 4E.

Additionally, an additional bridge member (or multiple bridge members)can extend between the two lower (as viewed in the orientation of FIG.4C) retractor elements 453, 454 independent of bridge member 444. Theseelements 453, 454 can help open up the lower section of the retractorsystem, and the bridge member(s), whether independent or connected tobridge 444, can help to stabilize these elements, e.g., limit side toside movement. Such bridge members on the lower retractor elements canbe used with the other retractor embodiments disclosed herein.

In some embodiments, each of the systems taught herein can have an outertube that is wire-reinforced, such as mesh, braided, or the like, toprovide kink resistance and torqueability to the system, as well as tofurther facilitate a positioning of the system in the subject.

FIGS. 4D and 4E illustrate oblique views of the system 400 in collapsedand expanded configurations. The multi-lumen concept is presented withclarity in these figures, showing multiple lumens 406 a, 406 b, 406 c inthe catheter 405 in system 400. Lumen 406 a can contain an endoscope(not shown) such as endoscope 315 described above, lumen 406 b cancontain a first working channel 410 b for a first endoscopic tool (notshown), and lumen 406 c can contain a second working channel 410 c for asecond endoscopic tool (not shown). The lumens 406 b, 406 c can receivethe first and second tools directly therein, or alternatively, receivetool channels (flexible guides) 410 b, 410 c like tool channels 310described above for angling the endoscopic tools slidably positionedtherein. FIG. 4D illustrates the system in the collapsed configurationand FIG. 4E illustrates the system in the expanded configuration. InFIG. 4E, the tool channels (flexible guides) 410 b and 410 c are shownexposed from the catheter 405 so their distal ends are in a curvedposition. The tool channels can be further advanced axially to align thecurved distal ends with the target tissue.

The system 400 also includes retractor elements 451, 452, 453 and 454.The retractor system further includes a flexible tube or beam 470 in thecollapsed configuration, whereas in the expanded configuration, theretractor system has a rigid beam 475 that was formed from the flexiblebeam 470. A rigid beam can be formed from a flexible beam, in someembodiments, by slidably inserting a rigid rod into a flexible tube thatcomposes the flexible beam. More specifically, in this embodiment, theflexible beam 470 slidably receives thereover a stabilizing orrigidifying structure such as a rigid rod. The rigidifying (stabilizing)structure can be independently actuated by the user by actuating acontrol, such as a slidable lever, operably connected to the rigidifyingstructure, such that movement of the actuator distally advances therigidifying structure over the flexible beam 470 to thereby stiffen thebeam. Alternatively, the flexible beam 470 can have a lumen to slidablyreceive therein a rigidifying structure such as a rigid rod. Thestructure in either version can optionally be retracted from theflexible beam 470 to return the system back to the original moreflexible state to aid collapsing of the retractor system. The beam 470can be substantially circular in cross-section, although othercross-sectional shapes are also contemplated. As in the aforedescribedembodiments, the rigid beam limits deflection of the distal end of thecatheter which could otherwise occur by pressure exerted on the distalend by the body lumen wall.

In many embodiments, the term “tool channel” can be used interchangeablywith the term “working channel “or tool guide.” And, in someembodiments, a channel can be a separate component placed inside theouter tube, or it can be a space remaining in the lumen of the outertube between separate components that were placed in the outer tube, theseparate components including, for example, an endoscope, a workingchannel, an instrument, a guide, and the like.

In some embodiments, as shown for example in FIGS. 4A-4E, the system cancomprise a stable, yet dynamic operative environment in that it caninclude a reversibly-expandable retractor 450 that expands to form atreatment space 460 in the subject. The retractor 450 can be configured,for example, for the expansion to occur distal to the distal end 408 ofthe outer tube 405. In some embodiments, the retractor can at leastsubstantially render the target tissue 490 aperistaltic for thetreatment. The retractor 450 can have a variety of configurations toserve, for example, as a scaffolding within the gastrointestinal tract495. For example, the retractor 450 can include retractor elements451,452,453,454, along with a proximal coupler 498 operably connected tothe retractor elements 451,452,453,454, whether at least substantiallyattached and/or at least slidably-engaged to the retractor elements451,452,453,454, and a distal nexus or coupler 499 for a distal point ofan operable connection with the retractor elements 451,452,453,454.Relative movement of the couplers 498, 499 can expand the retractorelements as described above. Alternatively, as described above, theretractor elements can be operably attached to a proximal actuator whichmoves the proximal portions relative to the fixed distal portions to bowthe retractor elements outwardly, which in preferred embodiments can bemade of superelastic material (although other materials arecontemplated), or shape memorized retractor elements can be utilized.

The retractor elements 451 and 452 can have a covering 451 a, 452 a,respectively, which add bulk to the retractor elements 451, 452 byincreasing its cross-sectional diameter. This is described in moredetail below in conjunction with the embodiment of FIGS. 6A-6D.

Moreover, the retractor 450 can be a reversibly-stabilized andreversibly-expandable retractor, the retractor 450 forming anasymmetrical treatment space upon the expansion. And, the retractor 450can be configured to reversibly stiffen an otherwise flexiblearrangement of the retractor 450, the arrangement designed to facilitateease of positioning of the system 400 in the subject and to reversiblystiffen for the expansion of the retractor 450. The stabilization of theretractor 450 can, in some embodiments, include stabilizing theretractor 450 through a stabilizer subsystem as taught herein, thestabilizer having, for example, an at least substantially-rigid beam 475to support the expanded retractor 450.

FIGS. 5A-5D illustrate side and top views of a system as taught herein,having side views and top views of expanded and collapsedconfigurations, according to some embodiments. The tool channels andtools are omitted for clarity, being similar to those described herein.FIGS. 5A and 5B illustrates side views of system 500 in collapsed andexpanded configurations showing an example of an asymmetric work spacethat can be formed during an endoscopic procedure using the system 500.And, as shown in FIG. 5B, as with the previously described embodiments,the expansion can occur in a disproportionally greater amount on theluminal side 559 of the rigid beam 575 than the abluminal side 557 ofthe rigid beam 575 to increase the treatment, or working space 560, thetreatment space 560 having a volume that is asymmetrically distributedaround the rigid beam 575. In some embodiments, the expansion of thevarious retractors systems disclosed herein can occur in an amount thatis at least 5× greater on the luminal side 559 of the rigid beam 575than the abluminal side 557 of the rigid beam 575. And in someembodiments, the expansion can be at least 1.1× greater, at least 1.3×greater, at least 1.5× greater, at least 2.0× greater, at least 2.5×greater, at least 3.0× greater, at least 3.5× greater, at least 4.0×greater, at least 4.5× greater, at least 5.0× greater, at least 5.5×greater, at least 6.0× greater, at least 6.5× greater, at least 7.0×greater, at least 7.5× greater, at least 8.0× greater, at least 8.5×greater, at least 9.0× greater, at least 9.5× greater, at least 10.0×greater, or any 0.1× increment within this range, on the luminal side ofthe beam than the abluminal side of the beam.

In some embodiments, as shown for example in FIGS. 5A-5D, the system cancomprise a stable, yet dynamic operative environment in that it caninclude a reversibly-expandable retractor 550 that expands to form atreatment space 560 in the subject. The retractor 550 can be configured,for example, for the expansion to occur distal to the distal end 508 ofthe outer tube 505. In some embodiments, the retractor can at leastsubstantially render the target tissue 590 aperistaltic for thetreatment. The retractor 550 can have a variety of configurations toserve, for example, as a scaffolding within the gastrointestinal tract595. For example, the retractor 550 can include retractor elements551,552,553,554, along with a proximal coupler 598 operably connected tothe retractor elements 551,552,553,554, whether at least substantiallyattached and/or at least slidably-engaged to the retractor elements551,552,553,554, and a distal nexus or coupler 599 for a distal point ofan operable connection with the retractor elements 551,552,553,554. Thecouplers 588, 599 can be relatively movable to expand the retractorelements 551, 552 (and optionally elements 553, 554 in the embodimentswhere they are expandable) in the same manner as the couplers describedabove, e.g., couplers 198, 199. The retractor elements can alternativelybe fixedly attached at their distal ends, e.g., to distal coupler 599,and operatively connected at proximal ends to an actuator or made ofself-expanding material such as shape memory material as in the variousembodiments described herein. Each retractor element 551, 552 in theembodiment of FIG. 5B expands to a substantially uniform (symmetric)arcuate shape, although alternatively they each can be configured toexpand to a non-uniform (non-symmetric) shape as in the embodimentsdescribed above. Note that in this embodiment where the retractorelements 551, 552 individually expand to a substantially symmetricshape, there expansion is on one side of the multi lumen outer tube 505,i.e., to only one side of a longitudinal plane through which alongitudinal axis passes. Therefore, their expansion with respect to theretractor system is asymmetric while their individual expanded shapemight be symmetric. Retractor elements 553, 554 have a slightly bowedconfiguration similar to retractor elements 353, 354. Retractor elements553, 554, positioned as the lower elements of the cage as viewed in theorientation of FIG. 5A, can have limited expansion or can be provided sothey do not expand when the retractor system expands but instead remainsubstantially in the same position. In such embodiments, the expandingretractor elements 551, 552 can be operably connected to an actuator andthe lower elements 553, 554 can be fixedly (non-movably) attached to thecatheter, e.g., to fixed proximal and distal couplers. Such attachmentalternative is also applicable to the other embodiments disclosed hereinwherein it is disclosed that the lower retractor elements maintainsubstantially the same position in the collapsed and expanded positionsof the retractor system.

Moreover, as with the retractors described hereinabove, the retractor550 can be a reversibly-stabilized and reversibly-expandable retractor,the retractor 550 forming an asymmetrical treatment space 560 upon theexpansion. And, the retractor 550 can be configured to reversiblystiffen an otherwise flexible arrangement of the retractor 550, thearrangement designed to facilitate ease of positioning of the system 500in the subject and to reversibly stiffen for the expansion of theretractor 550. The stabilization of the retractor 550 can, in someembodiments, include stabilizing the retractor 550 through a stabilizersubsystem as taught herein, the stabilizer having, for example, an atleast substantially-rigid beam 575 to support the expanded retractor550. In the embodiment of FIGS. 5A-5D, the rigid beam 575 can beprovided in a permanently stiffened condition as beam 175 of FIG. 1 , oralternatively can be formed by advancement of a rigidifying(stabilizing) structure over a flexible element or into the lumen of theflexible tubular member by an actuator as described above. In eithercase, the beam rigidifies the retractor system in the asymmetricalconfiguration creating the stable asymmetrical working space tofacilitate access and manipulation of the target tissue.

FIGS. 6A-6D illustrate side views of a system as taught herein havingside views and cross-sections of expanded and collapsed configurationsof the system, according to some embodiments. The figures illustrate anexample of a multi-lumen catheter system having a reversibly-stabilizedand reversibly-expandable retractor for a minimally invasive treatmentof a subject. FIGS. 6A and 6B illustrate a side view that shows that thesystem 600 can include a flexible outer tube 605 for guiding one or moretool channels (not shown) similar to the tool channels described aboveand an endoscope (not shown) similar to the endoscope described abovewithin the system 600. The flexible outer tube 605 has a lumen, aproximal end extending into the handle 680, and a distal end 608. Eachtool channel (serves as a guide through which a tool (not shown) can bemanipulated in a treatment of a target tissue in a subject. That is, thetool channels are configured to receive and reorient the tools insertedtherethrough as in the embodiments described above. In some embodiments,the retractor 650 can be a reversibly-stabilized andreversibly-expandable retractor 650 forming a treatment space 660 uponexpansion and configured for the expansion to occur distal to the distalend 608 of the outer tube 605. The retractor 650 can be designed toreversibly-stiffen an otherwise flexible arrangement of the retractor650, the flexible arrangement designed to facilitate the positioning ofthe system in the subject and to reversibly-stiffen for the expansion ofthe retractor 650. In these embodiments, the reversibly-stiffenedarrangement of the retractor 650 can form an at leastsubstantially-rigid beam 675 from an otherwise flexible beam 670 as astructural support for the expansion of the retractor 650.

Handle 680 at the proximal end includes entry ports for operativelycombining the system with external components, such as an entry port 609for an endoscope (not shown) and/or a tool (not shown). The handle 680is also operatively connected to the proximal end of the outer tube 605and can have exit ports from the handle 680 into the outer tube 605. Thesystem can include a stabilizer subsystem, in some embodiments. Forexample, a stabilizer actuator 612 can be included on the handle 680 toreversibly-stiffen the flexible beam 670 to create the at leastsubstantially-rigid beam 675 for the expansion of the retractor 650. Aretractor actuator 614 can be included on the handle 680 to reversiblyexpand the retractor 650. The retractor 650 is shown in FIGS. 6A and 6Bin the collapsed (non-expanded) condition.

FIGS. 6C and 6D illustrate oblique views of the system 600 in expandedconfigurations. The expanded configurations have a rigid beam 675 thatwas formed from the flexible beam that is typically present in thecollapsed state for positioning in the subject. The rigid beam 675 canbe formed from a flexible beam, in some embodiments, by slidablyinserting a rigid member (e.g., a rod) either over or alternatively intoa flexible member that composes the flexible beam to transform theflexible beam into a stiffer, more rigid beam. As shown in FIGS. 6B and6D, the stabilizer actuator 612 is operably connected to the rigidmember (stabilizing structure) such as rigid rod 672 through a rodcoupler 613. Consequently, movement of the actuator 612 in a firstdirection, e.g., a distal direction from a proximal position, will causethe stabilizing structure 672 to advance over the flexible beam 670 torigidify it (forming beam 675) to stabilize the retractor system, andmovement of the actuator 612 in a reverse, e.g., a proximal directionback to its proximal position, will retract the stabilizing structure672 from the flexible beam 670 to return the flexible beam 670 to itsmore flexible condition.

The retractor actuator 614 is operably connected to retractor elements651,652 through an element coupler 611. The stabilizer actuator 612and/or the retractor actuator 614 can be reversibly engageable with thehandle 680, in some embodiments, such that the stabilizer actuator 612and/or the retractor actuator 614 can be reversibly—fixed in positionrelative to the handle 680. In some embodiments, the stabilizer actuator612 and/or the retractor actuator 614 can be multi-positional, having atleast three positions for expansion and/or collapse of the retractor. Insome embodiments, the stabilizer actuator 612 and/or the retractoractuator 614 can have a plurality of ratchet teeth 616 to provide aplurality of positions for reversibly-fixing the stabilizer and/or forreversibly fixing the retractor in position during expansion or collapseof the retractor. As shown in FIG. 6B, in the proximal position of theretractor actuator 614, coupler 611 is in the proximal position and theretractor elements are in the non-expanded position. To expand theretractor elements, retractor actuator 614 is slid distally to move theattached coupler 611 distally, as shown in FIG. 6D, thereby causing theattached elements 651, 652 to bend outwardly due to their fixedconnection at their distal end to the distal coupler 699.

One of skill will appreciate that the handle can be any of a variety ofshapes to provide a desired or ergonomic position for operation of thesystem. By way of example, the retractor actuator can be configured as afinger-activated button on the handle 680 that slides back and forththrough a slot in the handle 680 to expand or collapse the retractorelements. A means for dynamically adjusting or ratcheting the retractorposition can be provided along the handle slot to lock the position ofthe retractor elements in place when the retractor actuator button isnot pressed. A button on the opposite side of the handle can beoperatively connected to the stabilizer subsystem to convert theflexible beam into a rigid beam, or convert the rigid beam into aflexible beam. The handle can have inner channels routed axially, forexample, within the body of the handle and in communication with portsfor tools and endoscope introduction into the outer tube. In someembodiments, the handle can be configured to require that the stabilizeractuator is activated before the retractor actuator can be activated,serving as a “safety” mechanism in the operation of the system.

As such, in some embodiments, as shown for example in FIGS. 6A-6D, thesystem can comprise a stable, yet dynamic operative environment in thatit can include a reversibly-expandable retractor 650 that expands toform a treatment space or working chamber 660 in the subject. Theretractor 650 can be configured, for example, for the expansion to occurdistal to the distal end 608 of the outer tube 605. In some embodiments,the retractor can at least substantially render the target tissue 690aperistaltic for the treatment. The retractor 650 can have a variety ofconfigurations to serve, for example, as a scaffolding within thegastrointestinal tract 695. For example, the retractor 650 can includeretractor elements 651,652,653,654, along with a proximal coupler 698operably connected to the retractor elements 651,652,653,654, whether atleast substantially attached and/or at least slidably-engaged to theretractor elements 651,652,653,654, and a distal nexus or coupler 699for a distal point of an operable connection with the retractor elements651,652,653,654. More specifically, the distal end of the retractorelements 651, 652 are attached within slots or openings in the proximalend of the distal coupler 699. The proximal ends of the retractorelements 651, 652 extend proximally through lumens in the catheter toattach to movable coupler 611. In this manner, with the distal ends ofthe retractor elements 651, 652 fixed, distal movement of the coupler611 forces retractor elements to bow outwardly as shown. Retractorelements 653, 654 can be attached to the distal coupler 699 and in someembodiments attached to movable coupler 611 if some expansion of theseretractor elements 653, 654 is desired, or alternatively, fixedlyattached to the catheter if expansion is not desired and expansion islimited to the retractor elements 651, 652.

It should be appreciated, that such couplers for retraction elementexpansion disclosed in FIGS. 6A-6D can be utilized with the otherembodiments of the retractor systems disclosed herein. Additionally, itshould be appreciated that alternative ways to expand the retractorelements can be utilized, including for example providing relativelymovable couplers 698, 699 to expand the retractor elements 651, 652,(and optionally 653, 654) in the same manner as the couplers describedabove, e.g., couplers 198, 199. The retractor elements can alsoalternatively be made of self-expanding material such as shape memorymaterial.

Each of the retractor elements 651, 652 in the embodiment of FIGS. 6A-6Dexpand to a substantially symmetric arcuate shape, althoughalternatively they can be configured to expand to an asymmetric shape asin the embodiments described above. Note that in in this embodimentwhere the retractor elements 651, 652 expand to a substantiallysymmetric shape, their expansion is on one side of a longitudinal axisof the multi lumen tube outer tube (catheter) 605. Therefore, theexpansion of the retractor system is asymmetric while their individualexpanded shape is substantially symmetric. Retractor elements 653, 654can optionally expand slightly outwardly in a bowed configuration. Theretractor element 651 can have a covering thereon. Similarly, retractorelement 652 can have a covering thereon. The covering extends over anintermediate portion of the elements 651, 652 and can be in the form ofa heat shrink tubing. The covering helps control expansion by providinga less flexible region. This covering is similar to covering 451 a and452 a of the embodiment of FIGS. 4D, 4E.

As described herein, the retractor 650 can be a reversibly-stabilizedand reversibly-expandable retractor, the retractor 650 forming anasymmetrical treatment space 660 upon the expansion. And, the retractor650 can be configured to reversibly stiffen an otherwise flexiblearrangement of the retractor 650, the arrangement designed to facilitateease of positioning of the system 600 in the subject and to reversiblystiffen for the expansion of the retractor 650. The stabilization of theretractor 650 can, in some embodiments, include a means for stabilizingthe retractor 650 through a stabilizer subsystem as taught herein, thestabilizer having, for example, an at least substantially-rigid beam 675to support the expanded retractor 650.

The rigid rod can be a straight component comprising a rigid material,for example stainless steel or another metal or alloy, that is slidablein and out of the inner diameter (lumen) of the flexible tube. As such,the stabilizer subsystem can have a flexible beam or rigid beam bysliding the rigid rod proximal (i.e., anally) to the flexible tube bypulling back on the rigid rod through a mechanism operably connected tothe handle. The rigid rod can be pushed forward (i.e., orally) into theflexible tube to stiffen and straighten the flexible tube as in theembodiments described above. By pushing the rigid rod across the lengthof the flexible tube, the flexible tube, or flexible beam, becomes rigidand straight, and in effect renders the whole retractor structure atleast substantially rigid and straight to stabilize the retractorsystem. One of skill in the art will appreciate that any mechanism ofreversibly stiffening a flexible component in vivo may be used in someembodiments. For example, the flexible tube, or flexible beam, may alsocomprise a series of rigid tubes having a flexible, non-stretchablecable passing through the lumens of the tubes. When the cable isrelaxed, the series of rigid tubes can be separated using, for example,a compressible component such as a spring between each of the series ofrigid tubes to provide a flexible non-overlapping configuration. Whenthe cable is tensioned, the compressible components compress, and therigid tubes overlap, converting the flexible beam into a rigid beam.Such alternative mechanisms can be utilized with any of the embodimentsdescribed herein.

The reversibly-stabilized retractor, as described herein, is useful inpositioning the working space at the site of treatment of the targettissue as it can be rendered flexible for positioning and later renderedrigid for expansion of the retractor. During introduction of a systemtaught herein into a tortuous body lumen, for example a colon, theretractor can be unexpanded and flexible. This flexibility allows theretractor to bend to conform to the bends in the tortuous body lumen, sothat it can be advanced with ease and not cause trauma to the lumen. Therings which hold the retractor elements together can also have lumensthat allow passage of a guide such as an endoscope. In such embodiments,when the retractor is in the flexible mode for introduction, forexample, the rings can be free to slide over the guide as the system isadvanced forward. In some embodiments, the lumens of the rings can belarge enough relative to the diameter of the guide to allow for tiltingand translation of the system on the guide, helping the system conformto the bends of the guide during advancement of the system orally oranally. Once the retractor is advanced to the target location in thelumen, the flexible beam of the retractor can be straightened andstiffened as described herein. Since the system can be flexible andtorsionally stiff, the proximal shaft or the handle can be easilyrotated as desired relative to the location of the target lesion.

The retractor elements can have at least one pair that is pre-shapedhaving peaks pointing outwards at a desired angle. In some embodiments,the angle can range from about 45 degrees to about 135 degrees, about 60degrees to about 120 degrees from each other on one side of the rigidbeam, the vertex of the angle being the central axis of the rigid beam,as can be seen in the figures provided herein. In some embodiments, theangle is about 90 degrees between retractor elements. Upon expansion,the retractor elements bulge outwards on one side disproportionally morethan the other retractor elements, resulting in an asymmetricalexpansion of the retractor. The at least substantially rigid beamprevents or inhibits deformation of the retractor during creation offorces on the retractor in the expansion and prevents or inhibitsbending of the catheter tip. The forces include forces from expandingtissue outwards asymmetrically, as well as the initial forces applied onthe retractor elements to create an asymmetrical working space.

In some embodiments, the target lesion can be located on the side of themost expanded retractor elements so to facilitate maximizing orincreasing the distance between the lesion to be treated and the portalsat which the endoscope and tools are introduced into the working space.The endoscope and tools can be maneuvered independently, for example, toaccess the lesion at a greater range of angles than is currentlyclinically obtainable using state-of-the-art systems. This increasedmaneuverability can improve the view of the lesion and ability tomanipulate and dissect the lesion. For example, a grasper can beadvanced out of the instrument channel into the working space and flexedtowards the polyp, grasp the polyp and retract the tissue to expose thebase of the polyp for dissection by a dissection tool through themulti-channel systems taught herein. Sometimes, it can also be desiredto reduce the distance between the lesion to be treated and the portalsat which the endoscope and tools are introduced into the working space.For example, it can be desired to locate the lesion on the side of theleast expanded retractor elements to better align the lesion with theendoscope channel substantially parallel to the lumen wall. Such aconfiguration may be clinically optimal while the polyp is retracted bya grasper towards the most expanded side. In such embodiments, adissection tool can be advanced through a channel at the base of thepolyp and dissect the polyp's base where it attaches to the lumen wall,while the position of the endoscope provides a close view of the base ofthe polyp to help identify the desired margin for dissection.

Any of the systems taught herein can include a bridge member, whichprovides structural support to add stability to the retractor. Thebridge member can include any configuration conceivable by one of skillto provide additional support, such as a scaffolding for enhancing orbuttressing the stability and rigidity of the expanded contractor. Forexample, bridge member 644 is configured to maintain a desiredorientation of the retractor elements 651,652,653,654 during theexpansion, the bridge member 644 operably stabilizing at least two651,652 of the four retractor elements 651,652,653,654. As shown, thebridge member outer portion in the collapsed position of the retractor650 extends radially outwardly and in the expanded position extends moredistally (see. FIG. 6D). Although only one bridge member 644 is shown,it is also contemplated that more than one bridge member could beprovided to connect retractor elements 651, 652. Additionally, one ormore bridge members can be provided to connect retractor elements 653,654 to stabilize and limit side to side movement of these elements aswell. Moreover, in some embodiments, each of the systems taught hereincan have an outer tube, for example outer tube 605, that iswire-reinforced, such as mesh, braided, or the like, to provide kinkresistance and torqueability to the system, as well as to furtherfacilitate a positioning of the system in the subject. In someembodiments, the bridge member 644 can be configured to reduce drag fromsurrounding tissue during use. For example, as shown in FIGS. 6A and 6B,the bridge member 644 can be configured to facilitate a movement of thesystem in a gastrointestinal tract by designing the bridge member 644 toinclude a forward component 644 a that is inclined to facilitate forwardmovement orally, and a reverse component 644 b that is inclined tofacilitate reverse movement anally.

The bridge member can be connected to the retractor elements, forexample, to maintain a desired orientation of the retractor elements asthey expand against a gastrointestinal tissue, for example. As theretractor is expanded, the bridge member is also expanded outward. Insome embodiments, the bridge member is operably connected only to theretractor elements that expand the most, for example the retractorelements 651,652 in FIG. 6 , which can be the members that incur themost induced forces on the retractor due to the disproportionatepressure applied to create the asymmetrical working space in theexpansion. In some embodiments, the bridge can be designed to flex toprevent the retractor elements from collapsing towards each other orbending away from each other, while also providing some spring orelasticity to the system to comply gently with the tissue. One of skillwill appreciate that the bridge member can comprise any suitablematerial that provides the material characteristics desired. Forexample, the bridge can be formed from a curved nitinol wire in someembodiments. The ends of the nitinol wires can be connected to theretractor elements using any manufacturing process deemed suitable byone of skill for the in vivo uses taught herein, such process including,for example, tubing connectors, adhesives, or solder.

FIG. 7 illustrates a cutaway view of the distal end of the outer tube ofa system 700 as taught herein, showing components of the expansion andcollapse of the retractor, according to some embodiments. The figureillustrates the distal end 708 of outer tube 705. The distal end 708includes a slot guide 755 to control the orientation of an expandingretractor element 751, as well as a port 754 a for operablyreceiving/supporting a lower retractor element 754. Another slot guide(not shown) can be provided to control the orientation of anotherretractor element. A lumen 706 c can be provided to contain a workingchannel 710 c for insertion of a tool channel as described above forinsertion of working instruments or alternatively for direct insertionof working instruments without a tool channel. The lumen 706 of theouter tube 705 can also be used to guide an endoscope (not shown)through an exit port in distal end 708. Only a portion of retractorcomponents 751, 754, 770, is shown to partially describe the relationbetween the outer tube 705 and the retractor in some embodiments. Theretractor can be configured, for example, for the expansion to occurdistal to the distal end 708 of the outer tube 705. For example, theretractor can include four retractor elements as in the embodimentsdescribed above, with retractor elements 751 and 754 shown and the twoother retractor elements not shown because of the cutaway view. Aproximal coupler 798 is operably connected to the four retractorelements, whether at least substantially attached and/or at leastslidably-engaged to the retractor elements. The retractor can beconfigured to reversibly stiffen an otherwise flexible arrangement ofthe retractor, the arrangement designed to facilitate ease ofpositioning of the system 700 in a subject and to reversibly stiffen forthe expansion of the retractor in the subject. The stabilization of theretractor can, in some embodiments, include stabilizing the retractorthrough a stabilizer subsystem as taught herein, the stabilizer having,for example, a flexible beam 770 that can be converted to an at leastsubstantially-rigid beam 775, by slidably engaging a rigid, orsubstantially rigid, component 772 as taught herein in operableconnection with the flexible beam 770, to support the expandedretractor. The flexible bean 770 can be stiffened in the mannersdescribed herein with respect to the flexible beams of the otherembodiments.

FIG. 8 illustrates a cutaway view similar to FIG. 7 , except in thisembodiment, a floating channel system is provided. That is, FIG. 8 showsthe distal end of the outer tube of a system as taught herein, in whichcomponents of the system can be floating in the outer tube to enhanceflexibility for positioning the system in a subject, according to someembodiments. The figure illustrates the distal end 808 of outer tube805. The distal end 808 includes a slot guide 855 to control theorientation of an expanding retractor element 851 and an opening 811 forlower retractor element 854. A second slot guide and a second opening(not shown) are provided to receive respectively another upper and lowerretractor element. A lumen 806 c can be provided to contain a workingchannel 810 c which receives a tool channel to guide a workinginstrument or alternatively directly receives a working instrument. Thelumen 806 of the outer tube 805 is used to guide an endoscope 815. Onlya portion of the retractor components 851, 854 are shown to partiallydescribe an embodiment of the relation between the outer tube 805 andthe retractor. The retractor can be configured, for example, for theexpansion to occur distal to the distal end 808 of the outer tube 805.For example, the retractor can include four retractor elements in thesame manner as described above, only two of which are shown (elements851 and 854). A proximal coupler 898 is operably connected to theretractor elements, whether at least substantially attached and/or atleast slidably-engaged to the retractor elements. The retractor can beconfigured to reversibly stiffen an otherwise flexible arrangement ofthe retractor, the arrangement designed to facilitate ease ofpositioning of the system 800 in a subject and to reversibly stiffen forthe expansion of the retractor in the subject. The stabilization of theretractor can, in some embodiments, include stabilizing the retractorthrough a stabilizer subsystem as taught herein, the stabilizer having,for example, a flexible beam 870 that can be converted to an at leastsubstantially-rigid beam in any of the manners described herein withrespect to the rigidifying of the flexible beam, e.g., slidably engaginga rigid, or substantially rigid, component 872 as taught herein inoperable connection with the flexible beam 870, to support the expandedretractor. As in the other embodiments described herein, an actuator canbe utilized which is operably coupled to the rigidifying structure toadvance and retract it with respect to the flexible beam 870.

The retractor elements are movable between a collapsed insertionposition and an expanded position to form an asymmetric working chamberas in the embodiments described above.

During a use of the system 800, the working channel 810 c can be afloating channel that is (i) at least substantially attached to thelumen of the outer tube at a first proximal location (not shown) and afirst distal location 806 c and (ii) at least substantially floating inthe lumen 806 of the outer tube 805 between the first proximal location(not shown) and the first distal location 806 c. Likewise, during theuse of the system 800, the endoscope 815 can be a floating endoscope 815that is (iii) at least slidably-attached to the lumen 806 of the outertube 805 at a second proximal location (not shown) and a second distallocation 806 a and (iv) at least substantially floating in the lumen 806of the outer tube 805 between the second proximal location (not shown)and second distal location (806 a). And, during the use of the system800, the working channel 810 c and the endoscope 815 also form separatefloating components of a floating arrangement that (v) at leastsubstantially increases the flexibility of the system 800 over a secondsuch system having separate lumens for a tool and an endoscope, theseparate lumens affixed to the lumen throughout the length of the outertube between the proximal end and the distal end of the outer tube, theincreased flexibility facilitating an ease of positioning the system 800in the subject for the treatment of the target tissue. In someembodiments, the endoscope 815 can be at least slidably-attached to thedistal end 808 of the outer tube 805 by inserting the endoscope 815through a dedicated port (not shown) for the endoscope 815, such thatthe system 800 is configured to be substantially limited to a slidingmovement in and out of the distal end 808 of the outer tube 805. And, insome embodiments, the endoscope 815 can be allowed to also float in aport 806 a that is substantially larger than the endoscope 815,providing a sliding motion for the endoscope as well as room forside-to-side movements as well.

FIGS. 9A and 9B illustrate side views of working, and/or floating,channels that can be used to guide tools as taught herein, according tosome embodiments. As discussed herein, the working channels can have atleast a portion of which floats in the lumen of the outer tube in amanner that is the same or similar to FIG. 8 to further enhance theflexibility of the outer tube during position of the system in asubject. In some embodiments, the terms “channel,” “floating channel”,and “tool channel” can be used interchangeably. Each tool channel can beoperatively connected to a handle 980 in a manner that is the same orsimilar to the operable connections taught herein for the retractoractuator and/or the stabilizer actuator. FIG. 9A shows the tip 910 a ofthe tool channel 910 in a substantially extended position, whereas FIG.9B shows the tip 910 a of the tool channel 910 in a substantially bentposition, such that the distal tip 910 a is deflected substantiallynormal to the central axis of the tool channel 910. A system 900consistent with other systems taught herein, for example, can include anentry port 909, a tool channel 91 inserted through entry port 909, awire coupler 911, ratchet teeth 916, a pull wire 917 for flexing orextending the tip 910 a of the working channel 910, and wire actuator919. The ability to flex the tip 910 a of the tool channel 910facilitates independent positioning of a tool (not shown) in thetreatment of a target tissue in a subject. In some embodiments, the wireactuator 919 can be multi-positional, having at least three positionsfor bending tip 910 a of tool channel 910. In some embodiments, the wireactuator 919 can have tooth engageable with one of a plurality ofratchet teeth 916 in handle housing 915 to provide a plurality ofpositions for reversibly-fixing the bent tip 910 a in position duringuse of the tool (not shown) in the treatment of the target tissue in thesubject. More specifically, when the wire actuator 919 is moved from itsdistal position of FIG. 9A to a more proximal position, it pulls pullwire 917, which is attached to the tip 910 a of tool channel 910,proximally to tension the tip 910 a, causing it to bend to theconfiguration of FIG. 9B. Engagement of the tooth of actuator 919 withthe teeth 916 maintains the position of actuator 919 and thus maintainsthe bent position of the tip 910 a. Note although the tip is shown bentat substantially 90 degrees to the longitudinal axis of the tool channel910, bending to other angles is also contemplated. Also, in someembodiments, actuator 919 is provided to control the angle of tip 910 aby controlling the degree of proximal retraction of the pull wire 917,with further retraction further bending the tip 910 a and lessretraction bending the tip 910 a to a lesser degree. More than one toolchannel can be provided, and the multiple tool channels can becontrolled by actuator 919, or alternatively, a separate actuator 919can be provided for each tool channel. Also, various mechanisms can beutilized to lock the actuator(s) 919 in position to maintain the bentposition of the tip of the tool channels.

Other mechanisms can also be utilized to control the tool channels.Alternatively, one or more of the tool channels can have a pre-bent(pre-curved) tip which is substantially straight when in the insertionposition within the confines of the multi-lumen tube (catheter) andreturns to the pre-bent position when exposed from the confines of thecatheter.

As described herein, the channels can be configured to control thetrajectory and position of instruments such as forceps in the workingspace created by the retractor. In some embodiments, a channel can beremoved from, or inserted through, the outer tube of the system, aloneor inside an additional channel that may be used as a guide. Thechannels can be virtually any size considered by one of skill to beuseful in the systems described herein. For example, a channel can havean inner diameter ranging from about 1 mm to about 5 mm, from about 2 mmto about 4 mm, from about 1 mm to about 3 mm, or any range therein. Thelength of the channel should, of course, complement the length of thesystem. For example, the channel can have a length ranging from about40″ to about 72″, from about 48″ to about 60″, from about 42″ to about70″, from about 44″ to about 68″, or any range therein in increments of1″.

The channels can also comprise any material or configuration known toone of skill to be suitable for the uses described herein. For example,the channels can comprise a single polymer layer, multiple polymerlayers, a wire reinforced layer, or a combination thereof. In someembodiments, a channel can comprise (i) an inner layer of a polymer suchas, for example TEFLON or polyethylene for slippery luminal surface onthe inner diameter of the channel; (ii) a metal such as, for example, astainless steel, nitinol, or cobalt chromium as a wire reinforcement inthe configuration of a braid, mesh, or helical coil layer covering theinner layer; and, (iii) an outer layer of a polymer such as, forexample, PEBAX, polyurethane, polyethylene, silicone, PVC, or nylon.

In some embodiments, the channels can be configured such that the outerlayer (iv) is the most rigid in the proximal section of the channel(i.e., the first about 12″ to about 24″ of the channel), having ahardness of about 60 Shore D to about 80 Shore D; (v) has a mediumstiffness in the middle section (i.e., the next about 12″ to about 36″of the channel), having a hardness of about 50 Shore D to about 72 ShoreD; and, (vi) is the most flexible in the distal section (i.e., the nextabout 0.5″ to about 2″ of the channel), having a hardness of about 20Shore D to about 50 Shore D). The distal section of the channel can bethe section that flexes and can be the distal about 1″ of the channel,in some embodiments. In some embodiments, the channels can have a rigidsection just proximal to the distal section to keep this flexiblesection straight when there is a bending moment on the tip such as whenthe instrument which is inserted through the channel is grasping atissue during a gastrointestinal treatment, for example. The length ofthe rigid section of the channels can range, for example, from about 1cm to about 10 cm, from about 2 cm to about 8 cm, from about 3 cm toabout 7 cm, from about 4 cm to about 6 cm, about 6 cm, or any rangetherein in 1 cm increments. The rigid section can include a rigid tubecomprising a reinforcement material such as, for example, stainlesssteel or NITINOL, or a polymer such as PEEK or a polyimide embeddedbetween the outer polymer layer and the inner polymer layer. The rigidsection can have any suitable length to perform its function in thesystem. In some embodiments, the rigid section can have a length rangingfrom about 0.001″ to about 0.005″.

The thickness of the inner layer of the channels can range from about0.0005″ to about 0.005″, from about 0.001″ to about 0.004″, from about0.002″ to about 0.003″, about 0.001″, or any range therein in 0.0005″increments. The thickness of the reinforcement layer can range fromabout 0.001″ to about 0.006,″ from about 0.002″ to about 0.005,″ fromabout 0.003″ to about 0.005,″ from about 0.001″ to about 0.003,″ about0.002″, or any range therein in increments of 0.0005″. The thickness ofthe outer layer can range from about 0.003″ to about 0.012″, from about0.004″ to about 0.010,″ from about 0.005″ to about 0.009,″ from about0.005″ to about 0.008,″ about 0.010″, or any range therein in incrementsof 0.001″.

For flexing the distal end of the channel, there can be a side lumenwith a pull wire embedded between the inner layer and the outer layer.In some embodiments, the side lumen can be located between the innerlayer and the reinforcement layer, or the side lumen can be a part ofthe inner layer. The side lumen can be made of any material consideredby one of skill to be useful in the systems taught herein. For example,the material can include a flexible tube of polymer such as, forexample, TEFLON or polyethylene. In some embodiments, the side lumenruns parallel to the length of the channel in the distal section of thechannel and then helical proximal to the distal section of the channel.The pitch of the helix can vary, for example, from about 1.0″ to about6.0″, from about 2.0″ to about 5.0″, from about 1.0″ to about 4.0″, fromabout 3.0″ to about 5.0″, about 4.0″, or any range therein in 0.1″increments. By routing the side lumen helically, the wire tension can bedistributed all around the shaft so that the shaft can be rotated in anyorientation smoothly and remain at least substantially stable. In someembodiments, the pull wire can run from the wire actuator in the handleinto the side lumen, out of the distal end of the side lumen, and loopedaround a rigid ring. The rigid ring (stainless steel, 0.002-0.005″thick, 0.040″-0.25″ long) at the distal end and back into the side lumenand out into the handle and attached to the wire actuator. The handlecan be operatively connected to the channel, the handle having ahousing, and a lumen in communication with the channel. The wireactuator is operatively attached to the pull-wire inside the housingwith a button on the outside of the handle allowing the wire actuator toslide back (proximal) and forth (distal) on the handle to pull and pushthe pull-wire. Pulling the wire makes the tip flex and become rigid,whereas pushing the wire can make the tip relax and straighten. Theslide has a means for locking the wire actuator in place, for example,using complementary ratchet teeth on the housing and wire actuatormechanism. When the wire actuator button is pressed, the ratchet teethcan disengage and unlock the pull-wire. In some embodiments, the tip canflex from about 0 degrees to about 150 degrees. In another embodiment,the tip can flexed from about 45 degrees to about 100 degrees. The canbe designed to be flexible in bending but stiff in torsion, allowing thechannel to follow the curvatures of the anatomy and allow for a rotationof the handle from outside the body during use, transmitting torque torotate the tip to a desired direction.

The tool (working) channels positioned inside the outer tube provide amulti-lumen catheter having manipulable passages for independentlymanipulating tools from outside the body into the working space insidecreated by expansion of the retractor. In some embodiments, from 1 to 3flexible tubes run inside of the outer tube and can be detached from theouter tube, as described herein, which facilitates the flexibility ofthe system. In some embodiments, these flexible tubes can be attached attwo points: (i) the proximal coupler of the retractor, which can be aring-type structure having ports at the distal end of the outer tube,and (ii) at the proximal end of the shaft, such as at the handle. Thiscan provide a floating arrangement in the outer tube that is unique,constraining the ends of the flexible tubes while allowing for asubstantially free-floating movement of the flexible tubes in the outertube to enhance the flexibility of the system.

In some embodiments, 2 inner tubes can be positioned adjacent to theinner surface of the outer tube to provide, effectively, 3 separatechannels. The 2 inner tubes can function as 2 independent tool channelswhile the space between these first 2 channels and the outer tubefunctions as a third channel. The third channel can be substantiallylarger than the other 2 channels. Each of the first 2 tool channels canhave, for example, an inner diameter ranging from about 2 mm to about 6mm, about 3 mm to about 5 mm, or any range therein. In some embodiments,the diameter of the first 2 tool channels can be about 4 mm. Each of thechannels can be designed to accommodate an endoscope such as acolonoscope, as well as endoscopic tools that include, for example,forceps, graspers, clip applier, dissectors, snares, electrical surgicalprobes, or loops. In some embodiments, the largest diameter channel canbe the channel for the endoscope.

The channel for accommodating the endoscope can be designed to have aninner diameter, for example, ranging from about 5 mm to about 15 mm,from about 6 mm to about 12 mm, from about 11 mm to about 14 mm, fromabout 5 mm to about 10 mm, from about 8 mm to about 13 mm, or any rangetherein in 1 mm increments. The inner tubes can comprise any suitablematerial known to one of skill to be useful for the purposes set-forthherein, as well as composites thereof. For example, the inner tubes cancomprise a fluoropolymer such as TEFLON for lubricity to ease tool orendoscope passage and movements. Other materials that may be usedinclude, for example, polyethylene, polypropylene, PEBAX, nylon,polyurethane, silicone, and composites thereof, each of which may alsobe used with a lubricant coating. The tubes may also comprise a metallicwire reinforcement such as a braid, mesh or helical coil, each of whichmay be embedded in the tube.

One of skill should appreciate that the systems taught herein can beused as a surgical suite with a floating, multi-lumen-catheter retractorsystem having a reversibly-stabilized and reversibly-expandableretractor for a minimally invasive treatment of a subject. In theseembodiments, the system can comprise a flexible outer tube for guiding afloating channel and a floating endoscope in a substantially floatingarrangement within the system. Due to the construction of the floatingsystem, the system is highly flexible, such that the flexible outer tubecan be highly flexible and have a lumen, a proximal end, and a distalend; and, the floating channel can serve as a guide through which a toolis manipulated in a treatment of a target tissue in a subject. Theretractor can be a reversibly-stabilized and reversibly-expandableretractor forming a treatment space upon expansion. The retractor can beconfigured, for example, for the expansion to occur distal to the distalend of the outer tube and to reversibly stiffen an otherwise flexiblearrangement of the retractor, the flexible arrangement designed tofacilitate the positioning of the system in the subject and toreversibly stiffen for the expansion of the retractor. That is, thesystem can include a stabilizing/rigidifying structure as in theembodiments described above, which can be slidable to rigidify theelement and retractor system.

During a use of the system, the floating channel can be (i) at leastslidably-attached to the lumen of the outer tube at a first proximallocation and a first distal location and (ii) at least substantiallyfloating in the lumen of the outer tube between the first proximallocation and the first distal location. Likewise, during the use of thesystem, the floating endoscope can be (iii) at least slidably-attachedto the lumen of the outer tube at a second proximal location and asecond distal location; and, (iv) at least substantially floating in thelumen of the outer tube between the second proximal location and seconddistal location. And, during the use of the system, the floatingarrangement can (v) at least substantially increase the flexibility ofthe system over a second such system having lumens for a tool and anendoscope, the lumens affixed to the lumen of the outer tube throughoutthe length between the proximal end and the distal end of the outertube. The increased flexibility can facilitate an ease of positioning ofthe system in the subject; and, the reversibly-stiffened arrangement ofthe retractor can form an at least substantially rigid beam as astructural support for the expansion in the subject for the treatment ofthe target tissue.

In some embodiments, the retractor comprises at least two expandableretractor elements, each of the members having a proximal end and adistal end, the proximal end slidably engaged with the outer tube, andeach of the members configured such that an increase in the amount ofsliding of the proximal end toward the distal end compresses the memberand expands the retractor. These embodiments can also include a distalnexus or coupler located distal to the distal end of the outer tube andat which the distal end of each of the at least two retractor elementsis affixed; and, a stabilizer subsystem connecting the distal nexus tothe distal end of the outer tube and having an at least substantiallyrigid component configured to reversibly stiffen an otherwise flexibleportion of the retractor for an asymmetric expansion of the retractor.

In some embodiments, the retractor comprises four expandable retractorelements, each of the members having a proximal end and a distal end,the proximal end slidably engaged with the outer tube, and each of themembers configured such that an increase in the amount of sliding of theproximal end toward the distal end compresses the member and expands theretractor. These embodiments can also include a proximal couplerattached to the distal end of the outer tube, the proximal couplerhaving four retractor ports for the slidable engagement with the fourretractor elements, the four retractor ports positionedcircumferentially around the proximal coupler and configured tofacilitate a reversible, axial sliding of the retractor elements for theasymmetric expansion of the retractor. These embodiments can alsoinclude a distal nexus or coupler located distal to the distal end ofthe outer tube and at which the distal ends of each of the fourretractor elements are affixed; and, a stabilizer subsystem connectingthe distal nexus to the distal end of the outer tube and having (i) aflexible component that extends from the proximal coupler to the distalnexus and (ii) an at least substantially rigid component that isslidably engaged with the proximal coupler and reversibly extends fromthe proximal coupler to the distal nexus to reversibly-stiffen theretractor in an asymmetric expansion of the retractor. The retractorelements can be moved to the expanded position in any of the waysdiscussed above. Also, if desired, only two of the retractor elementsexpand as in the embodiments described above.

The flexible component and the rigid component can have central axesthat are each at least substantially parallel to the central axis of thedistal end of the shaft, the rigid component forming an at leastsubstantially rigid beam as a structural support for the asymmetricexpansion, the rigid beam having a luminal side and an abluminal side.

The systems provided herein can be used in several different methods oftreatment. For example, the systems can be used in a method of treatinga gastrointestinal lesion using a multidirectional and multi-angularapproach to the lesion. The method can include positioning the system ina subject's gastrointestinal tract, the positioning including placingthe retractor in proximity to a target lesion for a treatment; expandingthe retractor to create the treatment space for use of the tool;treating the lesion with the tool; collapsing the retractor; and,withdrawing the system from the subject. The lesion can include, forexample, a perforation, a tissue pathology a polyp, a tumor, a canceroustissue, a bleed, a diverticuli, an ulcer, an abnormal vessel, or anappendix.

It should be appreciated that there are a number of procedures andvariations, in addition to those taught above, that can be used readilyby one of skill in the implementation of the systems taught herein. Insome embodiments, one of skill can insert the endoscope through theendoscope channel of the system and extend the distal end of theendoscope distal to the distal end of the retractor to form an assembly.The assembly can then be inserted into a body lumen or orifice, such asthe colon, and advanced orally until the distal end of the scope or thelens is in proximity to the target tissue (lesion or defect) to betreated. The system can then be advanced forward over the scope untilthe retractor is positioned over the distal end of the endoscope whileobserving the image from the endoscope. The system can be advanced untilthe target tissue is located between the proximal coupler and distalnexus of the retractor while observing the image from the endoscope. Thehandle or outer tube can be rotated to rotate the retractor so that thetarget tissue is at the desired position relative to the retractormembers while observing the image from the endoscope. The retractor canthen be straightened and stabilized by converting the flexible beam to arigid beam. The retractor can then be expanded by moving the retractionactuator forward on the handle while observing the image from theendoscope. This action pushes the tissue outwards, creates a workingspace around the target tissue, and anchors and stabilizes the targettissue. Optionally, while the retractor is expanded, the system can bepulled back to shift the peak of the most expanded members distally toimprove working distance between the endoscope and the peak of theasymmetric work space, wherein the peak is generally recommended to belocated around the target tissue. With the instruments inserted into theworking (tool) channels, insert the working channels into the proximalports of the system and advance the instruments and channels distallyuntil the tips of the working channels are distal to proximal coupler ofthe retractor while observing the image from the endoscope. At thistime, the tips of the working channels can be flexed to the appropriateangulation for the tools to approach the lesion to be treated. Theworking channels can be rotated and moved axially as needed to thedesired position for the tools. Likewise, the instruments/tools can beadvanced relative to the distal end of the working channels as needed toextend the instruments as needed to reach the target tissue. Variousinstruments can be inserted through the working channels as desired, andboth the endoscope and the instruments can be advanced and positionedindependently into the working area to further manipulate and visualizethe target tissue at closer proximities or angulations. This is because,in some embodiments, the endoscope can also flex within the workingspace.

In some embodiments, it's desirable to provide for delivering a systemtaught herein with an optional cover, or sheath that covers a portion ofthe system, including the retractor, during delivery of the retractor toa target site, during a treatment of a target tissue at the target site,during a removal of the target tissue, and/or during a removal of thesystem from the subject, or a combination thereof. Recall that someembodiments of such an optional cover 355 have been illustrated herein,for example, in FIGS. 3A and 3K. One of skill will appreciate that theretractor has elements that can catch, snag, or otherwise disturb orcontact tissue during delivery, or removal, of the retractor to or fromthe target site. Also, the treatment of the target tissue may include,for example a dissection of tissue that can be performed within thecover without intermingling the target tissue with the surroundingtissues. Moreover, the dissected tissue may be a cancerous or othertissue that is desirable to contain during treatment or removal byencapsulating it within the cover. The terms “cover” and “sheath” can beused interchangeably in many embodiments, and one of skill canappreciate that such embodiments are open to improvements, as taughtherein.

FIGS. 10A-10E illustrate a retractor sheath covering a retractor of asystem as taught herein, according to some embodiments. FIGS. 10A-10Cshow top, oblique, and side-views showing a flexible, clear sheath 1000that covers a collapsed configuration of the retractor 1050 to render anat least substantially smooth and/or atraumatic surface 1005 for adelivery of the retractor 1050 to a target site (not shown) for atreatment of a target tissue (not shown). In FIGS. 10A-10C, the cover isin a closed configuration that can be sustained until the expansion ofthe retractor 1050 for the treatment, or it can be reversibly-obtainedfollowing the treatment. FIGS. 10D and 10E show a top-view and side-viewof an expanded configuration of the retractor with the cover in an openconfiguration for the treatment.

The sheath 1000 can be designed to prevent or inhibit the retractorelements 1051,1052,1053,1054 and bridge members 1044 a, 1044 b fromcatching, snagging, or otherwise disturbing or contacting tissue duringa delivery or removal of the retractor 1050 to or from the target site.The sheath 1000 is attached at one end to the distal hub or coupler 1099and extends proximally past the proximal coupler or hub 1098 and isattached to the outer surface of the catheter 1055. Alternatively, thesheath 100 can be attached at a proximal end to proximal coupler 1098.Retainers can be used at any position around the retractor to facilitatea retention of the configuration of the working space 1060, for example,to retain the configuration under forces of the expansion of theretractor 1050. During the procedure the sheath 1000 can also prevent orinhibit tissue from entering the retractor 1050 until desired. Thesheath 1000 can also act as a collection means for entrapping and/orpulling out a resected tissue, which can be particularly desirable inthe resection of cancerous tissue in some embodiments. The sheath 1000can be at least substantially closed around the retractor 1050 duringdelivery, and can be designed to open as the retractor 1050 is expandedto create the working space 1060 for the treatment. Alternatively, theexpansion of the retractor elements and the sheath can be independent.

A flexible beam 1070 can be converted to the at least substantiallyrigid beam 1075 using the methods and structure of conversion asdescribed above in conjunction with the other embodiments. For example,an actuator can be operably connected to the beam (rigidifyingstructure) 1075 to advance it into a lumen of the flexible beam 1070, oralternatively advance it over the flexible beam 1070 (as shown in FIG.10D), to stiffen (make more rigid) the flexible beam 1070. The bridgemember 1044 a can connect the expandable retractor elements 1051, 1052and bridge member 1044 b can connect elements 1053, 1054 to restrictlateral movement and stabilize the retractor as in the other bridgemembers described herein. In alternate embodiments, bridge member 1044 bextends from bridge member 1044 a and connects to elements 1053, 1054such that all four elements 1051, 1052, 1053 and 1054 are connected bythe bridge elements 1044 a, 1044 b. Bridge member 1044 c can connectelements 1053, 1054. Coverings 1051 a and 1052 a can be applied to theretractor elements 1051, 1052, respectively, to control expansion asdescribed in the embodiment of FIG. 11 below.

In some embodiments, the sheath 1000 can be perforated longitudinally(not shown), designed such that the sheath 1000 opens upon expansion ofthe retractor 1050 through tearing of the perforation at the targetsite. In some embodiments, a tongue-and-groove mechanism, for example aZIPLOCK mechanism, can be used to at least substantially close a slit1007 at the top of the retractor 1050 which can also open upon theexpansion of the retractor 1050 at the target site. In some embodiments,a larger perforation, or unclosed portion 1001, can remain in the sheath1000 to facilitate the tearing or opening of the sheath at the targetsite upon the expansion of the retractor 1050. In some embodiments, theterms “slit” and “opening” can be used interchangeably.

In some embodiments, the sheath can be reversibly opened, such that thesheath can be re-closable. For example, a drawstring, cable, or wire,can be operably positioned in communication with the opening for there-closing of the opening by pulling or pushing the drawstring, cable,or wire from outside the patient during the treatment. In someembodiments, the edges of the opening can form longitudinal pockets orchannels for pulling or pushing the drawstring, cable, or wire asdesired from outside the patient during the treatment, such as byrouting the drawstring, cable, or wire through the system and, perhaps,through the handle as with the other actuation means. In someembodiments, a drawstring is used to re-close the sheath, wherein thestrings can be tensioned at the handle to close the slit, or loosened toallow the retractor to expand. In some embodiments, the sheath has astiffening strip running transversely around the mid portion of the cageto facilitate the cage wires expanding without catching on thesurrounding sheath. The stiffening strip can be another layer of thesheath welded or glued onto the existing sheath. It can also be formedas a thickened area. Alternatively, a stiffer material can be insertedin the pocket running transversely. The stiffening material may be thesame as that of the sheath or it may be a stiffer material.

One of skill will appreciate that any of the known materials and/ormethods of covering the sheath may be useful for the purposes taughtherein. For example, the sheath can range from about 10 mm to about 30mm at the ends that are attached to the proximal coupler and distalnexus, each of which can be used to define the ends of the retractor1050. Moreover, the sheath can be heat welded, glued, or heat-shrunk tothe proximal coupler and/or distal nexus, or perhaps substantiallyproximal or distal to these components, to fasten the sheath to theretractor. In some embodiments, the sheath may even cover the system asa sterilizing, or clean, cover, such that the sheath is an extension ofa disposable and/or replaceable component that may be applied, forexample, in a sterilization process. And, in some embodiments, thesheath can be larger at the mid portion where the diameter can range,for example, from about 20 mm to about 40 mm in a closed configuration.The sheath can be, for example, opaque, translucent, or clear, and thematerial composing the sheath can be, for example, a polyethylene,nylon, fluorinated ethylene propylene (FEP), TEFLON, polyethyleneterephthalate (PET), or polycarbonate. And, in some embodiments, thesheath material can range, for example, from about 0.0010″ to about0.0060″ thick, from about 0.0020 to about 0.0080″ thick, from about0.0030″ to about 0.0050″ thick, from about 0.0010″ to about 0.0030″thick, from about 0.0005″ to about 0.0100″ thick, about 0.0020″ thick,or any range therein in about 0.0005″ increments.

In use, when the retractor system 1050 is moved from the collapsedinsertion position of FIG. 10B to the expanded position of FIG. 10E, theexpandable retractor elements are expanded away from the sheath 1000.The sheath 1000 can remain open at a surface facing the target tissue tobe treated, e.g., removed, from the patient's body. Alternatively, thesheath 1000 can remain closed and be opened by an endoscopic tool toreceive the removed lesion. Note as shown in FIG. 10E, in the expandedposition, the sheath 1000 is covering the retractor elements 1053, 1054and rigid beam 1075 and is spaced from expanded elements 1051, 1052. Inalternate embodiments, the sheath can also cover elements 1051, 1052 intheir expanded configuration.

FIGS. 11-30 illustrate alternative embodiments of the system, designatedgenerally by reference numeral 1100. System 1100 includes a multi-lumencatheter or tubular member 1110 configured to receive one or more toolchannels or flexible instrument guides. FIG. 11 shows two tool channels1122 and 1124, it being understood that in some embodiments, only onetool channel can be utilized and in other embodiments more than two toolchannels can be utilized, with the catheter provided with a sufficientnumber of lumens. The tool channels 1122, 1124 can be packaged as a kitwith the catheter 1110 as shown in FIG. 11 . Alternatively, the toolchannels 1122, 1124 can be packaged separately. In other embodiments,the tool channels are packaged already inside the lumens of the catheter1110. Each tool channel 1122, 1124 has a lumen (channel) to receive anendoscopic instrument (tool) therethrough.

The tool channels (also referred to herein as flexible tubes or flexibleguides) 1122 and 1124 are inserted through the proximal end of thecatheter 1110 and advanced through respective lumens 1112, 1114 in thecatheter 1110 (see FIG. 12 ). As shown in FIG. 16 , which illustrates aproximal portion 1113 of catheter 1110, the catheter 1110 can includeports 1115, 1117, cooperating with the lumens 1112, 1114, respectively(see e.g. FIG. 13 ), which can include valves to maintain insufflationwhen the tool channels 1122, 1124 are inserted therethrough andtranslated axially therein. Tool channel (tube) 1122 preferably has apre-bent tip 1122 a, best shown in FIGS. 11 and 18 , to provide a curveddistal end. Tool channel (tube) 1124 also preferably has a pre-bent tip1124 a, providing a curved distal end. When the tool channels 1122, 1124are inserted into the lumens 1112, 1114 of catheter 1110, the tips 1122a, 1124 a are preferably substantially straightened to facilitateadvancement through the lumens. When the tool channels 1122, 1124 areadvanced sufficiently distally so the distal tips 1122 a, 1124 a areexposed from the confines of the walls of the catheter lumens 1112,1114, the tips 1122 a, 1124 a, return to the pre-set curved position.This can be understood with reference to FIG. 18 which illustrates inphantom the straightened position of the tool channels 1122, 1124 formovement within the catheter 1110. As in the other embodiments disclosedherein, the tool channels 1122, 1124 can be composed of superelasticmaterial, although other materials to provide the curved tip whichreturns from a substantially straight insertion shape to a curved shapewhen exposed can also be used, such as stainless steel. Also, as in theother embodiments disclosed herein, shape memory properties of materialsuch as Nitinol can be used with a memorized curved tip shape. Inalternative embodiments as described above, the tool channels 1122, 1124can have a mechanism such as a pull wire which is actuated to bend itsdistal end. The tool channels 1122, 1124 in the embodiments of FIGS.11-30 are unattached to the catheter 1110 so that the user can freelycontrol their axial movement from a proximal end portion 1122 b, 1124 b,during use. However, it is also contemplated that in alternateembodiments the tool channels can be attached to the catheter.

The tool channels 1122, 1124 can optionally include markings 1123, 1125,respectively, at a region proximal to the catheter 1110 to provide avisual indicator to the user of the depth of insertion of the toolchannels 1122, 1124 through the catheter lumens 1112, 1114. The toolchannels 1122, 1124 can have a luer fitting 1127, 1129, respectively,(FIGS. 11 and 19A) with a valve, at the proximal end which can close offbackflow of insufflation gas from the body. This maintains insufflationwhen the endoscopic tool is inserted through the tool channels 1122,1124 as described below. The tool channels in an alternate embodimentshown in FIG. 19B have a hemostatic valve 1121A, 1121B connected at aproximal end of tool channels 1122′, 1124′, respectively, to maintaininsufflation during tool insertion. As shown, valves 1121A, 1121B areproximal of luer fittings 1127′, 1129′. The tool channels 1124′, 1126′are identical to tool channels 1124, 1126 in all other respects.

In one embodiment, the tool channels 1122, 1124 can be composed of aflexible soft material, such as Pebax. A superelastic nitinol backbonecan in some embodiments be embedded in the wall of the Pebax material,e.g., within the curved portion. Other materials are also contemplated.

Catheter 1110 also preferably has a lumen 1116 (see e.g., FIG. 16 )configured and dimensioned to receive an endoscope 1200. In someembodiments, the lumen 1116 is dimensioned to receive a conventionalendoscope, e.g., a conventional colonoscope, and the catheter 1110 isbackloaded over the endoscope. This is described in more detail below inconjunction with the method of use. In alternate embodiments, the lumen1116 can receive an articulating endoscope. Moreover, in alternateembodiments, the endoscope can be inserted into the catheter andinserted into the body lumen.

With reference to FIGS. 11 and 16 , catheter 1110 includes a handlehousing 1130 at the proximal portion 1113 which contains two actuators:actuator 1132 for controlling movement of the retractor system 1150 andactuator 1134 for controlling movement of the rigidifying (stabilizing)structure. These are discussed in more detail below. Catheter 1110 alsoincludes tubing 1139 having a luer coupling 1137 and a control switch1175 (see FIGS. 31A, 31B) for closing off an internal gasket 1176. Thestring, e.g., suture, 1172 for closing covering 1170 is secured by theelastomeric gasket 1176 as the switch 1174 is moved from the position ofFIG. 31A to the position of FIG. 31B. More particularly, in the initialposition of FIG. 31A, the ball valve 1174, seated in a slot in thehousing 1179, does not apply a force to the gasket 1176. This enablesthe suture 1172 to freely move within the lumen of the catheter. When itis desired to lock the suture 1172 in position, i.e., after the suture1172 is tensioned to close the covering 1170, the switch 1175 is slidforward, thereby camming the ball 1174 downwardly (as viewed in theorientation of FIG. 31B) to collapse the lumen in the gasket 1176against the suture 1172 to thereby secure the suture 1172. This locksthe suture 1172 against movement which thereby maintains the covering(bag) in the closed position encapsulating the target tissue asdescribed herein. Note that the reverse movement of the switch 1175unlocks the suture 1172 to enable free movement of the suture 1172.Catheter 1110 also has tubing 1136 having a one-way stopcock 1138 toprovide an insufflation port. This port can be used to supplement theinsufflation gas provided by the endoscope 1200. The insufflation gasflows through lumen 1116 in the area around the endoscope 1200 since thecross sectional dimension of the lumen 1116 exceeds the cross-sectionaldimension of the endoscope 1200 to leave a sufficient gap. As shown, thetubings 1139, 1136 are positioned distal of the actuators 1132, 1134,

Turning now to the retractor system 1150, which forms a working spaceexpanding system, and in certain clinical applications, a body lumenreshaping or reconfiguring system, and with initial reference to FIG. 13, the retractor system 1150 is positioned at the distal portion 1111 ofthe catheter 1110 (distal of proximal hub 1140) and includes flexibleretractor elements 1152 and 1154. Retractor system also includesretractor elements 1156 and 1158. Retractor elements 1152, 1154 form theexpandable elements which create the working chamber (space) within thebody lumen and form an asymmetric cage. Retractor elements 1156, 1158form the base of the retractor system, thus helping to define theretractor cage along with elements 1152, 1154. In some embodiments,retractor elements 1156, 1158 do not undergo any change when theretractor system 1150 moves from the collapsed insertion position to theexpanded position; in other embodiments, retractor elements 1156, 1158undergo a slight change in position, i.e., slight expansion or bowing,when the retractor system 1150 is expanded. Retractor elements 1152,1154, are expandable to form an asymmetric working chamber to improvevisibility and working space as described in detail above with respectto the other systems forming asymmetrical working spaces.

As shown by comparing FIGS. 15 and 21A, retractor elements 1152 and 1154move from a collapsed insertion position wherein they preferably do notextend beyond, or significantly beyond, the transverse dimension of thecatheter 1110 to an expanded position wherein they bow laterallyoutwardly and have a transverse dimension extending beyond thetransverse dimension of the catheter 1110. Also by comparing FIGS. 15and 21A, it can be seen that lower (as viewed in the orientation ofthese figures) elements 1156, 1158 in the collapsed position do notextend beyond, or significantly beyond, the transverse dimension of thecatheter 1110 and when the retractor is expanded, remain substantiallyin the same position so they still do not extend beyond, orsignificantly beyond, the transverse dimension of the catheter 1110. Insome embodiments, the elements 1156, 1158 do not extend at all beyondthe transverse dimension of the catheter 1110. As in the embodimentsdescribed above, the retractor system 1150, i.e., the retractor elements1152, 1154, expand to only one side of a plane passing through alongitudinal axis of the catheter 1110, thereby creating the asymmetricworking space 1151 (and asymmetric cage), with its attendant advantagesdescribed herein.

Retractor elements 1152, 1154 have a bridge member 1155 to add stabilityto the retractor and maintain a desired orientation of the retractorelements during the expansion. The bridge member 1155 is attached to thetwo retractor elements 1152, 1154, preferably at an intermediateportion, to create a transverse structure for the elements 1152, 1154,limiting side-to side movement. As shown, bridge member 1155 has a firstarm 1155 a connected to retractor element 1152 and a second arm 1155 bconnected to retractor element 1154. The upper surface (as viewed in theorientation of FIG. 15 ) can be arcuate as shown. The bridge member 1155can be a separate component attached to the retractor elements bytubular elements 1159 a, 1159 b, which are fitted over and attached toretractor elements 1152, 1154, respectively. In this version, thetubular element 1159 a, 1159 b has a first opening to receive theretractor element and a second opening to receive an arm of the bridgemember, although alternatively they can both be received in the sameopening. Note the tubular elements 1159 a, 1159 b also bulk up thediameter of the retractor elements 1152, 1154 since in some embodimentsthe retractor elements 1152, 1154 are about 0.035 inches in diameter(although other dimensions are contemplated). Other methods ofattachment of the bridge members are also contemplated. Alternately, thebridge member 1155 can be integrally formed with one or both of theretractor elements 1152, 1154. The bridge member 1155 can be composed ofa material similar to the elements 1152, 1154 or can be composed of adifferent material. The bridge member 1155 can also include legs 1155 dand 1155 e which are connected to lower elements 1158, 1156,respectively, to attach the bridge member to lower elements 1158, 1156,respectively, to add to the stability of the retractor system. These legmembers 1155 d, 1155 e are preferably composed of soft elastomericmaterial such as polyurethane tubing to add more structure to the cageand facilitate expansion of the cage in a more predictable fashion.

Additional bridge members (not shown) can be provided on the retractorelements 1052, 1054 to increase stability. The bridge member 1055 can,in some embodiments, in the collapsed position, extend substantiallyaxially as in FIGS. 15 and 17A, but change to angle inwardly(downwardly) toward the longitudinal axis of the catheter 1010 in theexpanded position of the retractor elements 1052, 1054 such as in FIG.21A.

An additional bridge member 1157 (or alternatively multiple bridgemembers) extends between the two lower (as viewed in orientation of FIG.15 ) retractor elements 1156, 1158. These elements 1156, 1158 can helpopen up the lower section of the retractor system 1150 and help form thecage for the working space, and the bridge member(s) 1157 can help tostabilize these elements 1156, 1158, e.g., limit side to side movement.The bridge member 1157 as shown has arms 1157 a, 1157 b connecting toelements 1156, 1158, respectively. The bridge member 1057 can be aseparate component attached to the retractor elements by tubularelements 1161 a, 1161 b which are fitted over and attached to retractorelements 1156, 1158, respectively. The tubular elements 1161 a, 1161 bcan have a first opening to receive the element 1156 or 1158 and asecond opening to receive an arm of the bridge member 1157, althoughalternatively they can both be received in the same opening. Other waysof attaching the bridge member(s) are also contemplated. Alternatively,the bridge member 1157 can be integrally formed with one or both of theretractor elements 1156, 1158. The bridge member 1157 can be composed ofa material similar to the elements 1156, 1158 or can be composed of adifferent material.

Additional bridge members (not shown) can be provided on the retractorelements 1156, 1158 to increase stability. The bridge member 1157 can,in some embodiments, in the collapsed position, be substantiallyparallel with a longitudinal axis of the catheter 1110 or extendsubstantially axially such as in FIG. 15 , and substantially remain inthis position in the expanded position of the retractor elements 1152,1154 as in FIG. 21A since in this embodiment, the retractor elements1156, 1158 remain in substantially the same position when the retractorsystem 1150 is expanded

The catheter 1110 includes a proximal coupler (cap) 1140 through whichthe retractor elements extend. Handle housing 1130 includes alongitudinally extending slot 1131 (FIG. 16 ) along which retractoractuator 1132 axially slides. The retractor elements 1152, 1154 arecoupled to the actuator 1132 via block 1146, shown in FIGS. 20A and 20B.That is, each retractor element 1152, 1152 has a proximal extension thatextends through the respective lumen 1112, 1114 in the catheter 1150 andis connected at its proximal end to the block 1146. In this manner, whenthe actuator 1132 is moved along axial slot 1131 from its proximalposition of FIG. 20A to its distal position of FIG. 20B, the block 1146is moved distally, thereby forcing the retractor elements 1152, 1154laterally outwardly since the elements 1152, 1154 are fixedly attachedto the distal coupler 1148 at their distal ends. Elements 1156, 1158 inthis embodiment, are fixedly attached to the distal coupler 1148 attheir distal ends, and fixedly attached to the proximal coupler 1140 (orother portion of the catheter 1110) at their proximal ends such thatmovement of actuator 1132 does not effect movement of these elements1156, 1158. It should be appreciated, however, that if it is desired tohave the elements 1156, 1158 move, e.g., flex slightly outwardly whenthe retractor 1150 is expanded, these elements 1156, 1158 can beattached to the block 1146 so they would be moved when actuator 1132 isadvanced, or alternatively attached to a separate actuator. In oneembodiment, the elements 1152, 1154, 1156 and 1158 can be fixed withinslots formed in the distal coupler 1148. Note the proximal and distalcouplers 1140, 1148 can have openings dimensioned to receive anendoscope when the catheter 1110 is backloaded over the endoscope asdescribed below. Housing 1130 can include a plurality of teeth (notshown) similar to the teeth of FIGS. 6A-6D for engagement by a toothcoupled to the actuator 1132, thereby forming a retaining or lockingmechanism to retain the retractor elements in one of several selectpositions. A release mechanism for the retaining or locking mechanismcan be provided.

Additionally, it should be appreciated that alternative ways to expandthe retractor elements can be utilized, including for example providingrelatively movable couplers 1140, 1148 to expand the retractor elements1152, 1154 (and optionally 1156, 1158) in the same manner as thecouplers described above, e.g., couplers 198, 199. The retractorelements can also alternatively be made of self-expanding material, suchas shape memory material, which expand when exposed from the catheter orsheath.

Retractor elements 1152, 1154 can optionally have a small crimp forminga flattened position at a distal end adjacent where they are anchored tothe distal coupler 1148. This reduces the bending stiffness at the pointso it acts like a hinge to create a more predictable direction ofexpansion, e.g., to deflect upwardly and slightly outwardly. This alsodecreases the amount of force required to initiate the bending. Suchflattened portion can also be used with the retractor elements of theother embodiments disclosed herein.

The retractor system 1150 can be configured to reversibly stiffen anotherwise flexible arrangement of the retractor 1150. In this regard,retractor system 1150 can include a substantially-rigid beam to supportthe expanded retractor 1150 which helps to create a more stabilizedchamber (or cage) as described herein. With reference to FIGS. 15 and17A, a flexible tube or beam 1160 is provided in the collapsedconfiguration, whereas in FIG. 17B, the retractor system has a rigidbeam that is formed from the flexible beam 1160. More specifically, inthis embodiment, the flexible beam 1160 is in the form of a rod or tube1165 having a lumen to slidably receive therein a stabilizing orrigidifying structure such as a rigid tube or rod (beam) 1162. Therigidifying (stabilizing) structure 1162 is independently actuated bythe user by movement of actuator 1134. Actuator 1134 is slidably mountedwithin a longitudinally extending slot of housing 1130. In the initialposition of FIG. 17A, rigidifying structure 1162 is retracted within alumen of the catheter and either not engaged, or only partially engaged,with flexible tube (or rod) 1160. Rigidifying structure 1162 attached atits proximal end to sliding block 1164 which is operably connected toactuator 1134. To rigidify tube 1160, actuator 1134 is slid distally tothe position of FIG. 17B, thereby advancing sliding block 1164 and theattached stabilizing structure 1162 distally. Such movement advances therigidifying structure 1162 through the lumen 1165 of the flexible tube1160 to the distal end 1160 a to thereby stiffen the beam. Therigidifying structure 1162 can optionally be removed from the flexiblebeam 1060 to return the system back to the original more flexible stateto aid collapsing of the retractor system 1050 by sliding the actuator1134 in the reverse direction (proximally) within the axial slot,thereby withdrawing rigidifying structure 1162 from the advancedposition within flexible tube 1160. In one embodiment, the rigidifyingstructure 1162 is in the form of a structure having a proximal anddistal metal tubular structure joined by a flexible braid polyimidetube. However, it should be appreciated that other structures are alsocontemplated. Note the structures 1160, 1162 can be substantiallycircular in cross-section, although other cross-sectional shapes arealso contemplated. As in the aforedescribed embodiments, the rigid beamlimits deflection of the distal end 1111 of the catheter 1110 whichcould otherwise occur by pressure exerted on the distal end by the bodylumen wall.

As shown in FIGS. 17A and 17B, the actuator can include a connector 1135having a tooth or pawl 1137 to engage a tooth on the rack 1138positioned within housing 1130 to retain the rigidifying structure 1164in one of several selected positions.

In the alternate embodiment of FIGS. 17C and 17D, instead of advancing arigidifying structure within the lumen of the flexible element, therigidifying structure is advanced over the flexible element. Morespecifically, flexible beam 1160′ is rigidified by movement of arigidifying structure, e.g., tubular member 1162′, over the flexiblebeam 1160′. That is, rigidifying member 1162′ has a lumen configured anddimensioned to receive flexible beam 1160′ as it is passed thereover inthe direction of the arrow of FIG. 17C. Note that flexible element 1152has been removed from FIGS. 17C and 17D for clarity. Actuator 1134, aswell as alternative methods, can be utilized for such movement.

A covering or cover 1170 is preferably provided at a distal end of thecatheter 1110. Covering 1170 in the illustrated embodiment is mountedaround the perimeter of the proximal coupler 1140 and the distal coupler1148. In some embodiments, the cover 1170 is pleated and sealed aroundthe couplers (caps) 1140, 1148 by a heat shrink wrap. The cover 1170 ispositioned around the elements 1152, 1154, 1156, 1158 in the collapsedinsertion position, with an opening in the cover 1170 facing toward thetarget tissue, e.g., the lesion to be removed. That is, in theorientation of FIG. 15 , the opening in cover 1170 faces upwardly. Thecover 1170 can be configured to have an opening in the collapsedposition, or, alternatively, it can provided with a slit which can beopened due to stretching when the retractor elements 1152, 1154 aremoved to the expanded position. When the retractor elements 1152, 1154are expanded, they move past the cover 1170 toward the target tissue.Alternatively, the edges of the cover 1170 can be attached to theretractor elements 1152, 1154 and thereby move with the retractorelements. When the target tissue is removed by the endoscopicinstruments described herein, the removed tissue is placed within thecover 1170, and the cover 1170 is closed, e.g., by a string or suture1172 shown in FIG. 29 to encapsulate the tissue and prevent leakage andseeding during removal from the body lumen. The suture 1172 can beembedded in a wall of the cover 1170 or in pockets or channels formed inthe cover 1170, where it is permanently fixed at a distal anchor point,and pulled proximally to tension the suture 1172 and close the cover1170.

As with the cover (sheath) 1000 of FIG. 10 , the cover 1170 by coveringthe retractor elements 1152, 1154, 1156, 1158 can provide a smooth andatraumatic surface for the delivery of the retractor system to thetarget site. The cover 1170, like cover 1000, also helps to preventtissue, e.g. the luminal walls, from entering through the spaces betweenthe beam 1160 and elements 1156, 1158 during the surgical procedure.

In a preferred embodiment, the two ends of suture 1172 extend out oftubing 1139. Their proximal ends can be covered by a length of tubing tofacilitate grasping by the user. The suture 1172 extends through switch1137 and tubing 1139, through a dedicated lumen (channel) in thecatheter, through the covering 1170, and is looped at the distal cap1148 where it is attached (anchored). During the procedure, the suture1172 remains untensioned. After the tissue is placed within the cover(bag) 1170, the two proximal ends of the looped suture 1172 are pulledproximally to tension the suture 1172 to close the cover 1170. Theswitch can then be moved to frictionally engage to the suture 1172 tosecure it so it locks in the tensioned position to maintain closure ofthe cover 1170.

The use of the system of FIG. 11 will now be described with reference toremoving a lesion, such as a polyp, from a colon wall, it beingunderstood, however, that the system 1100 can used for other procedureswithin the colon or the gastrointestinal tract, as well as used forother procedures in other body lumens or body spaces of a patient.

Turning first to FIGS. 12 and 13 , a distal viewing endoscope 1200, inwhich the system 1100 has been advanced over the proximal end 1201 asshown in FIG. 12 , or alternatively the system 1100 backloaded over thedistal end of the endoscope 1200, is inserted through lumen A in thecolon B in a procedure to remove the target polyp C from the wall of thecolon B. The endoscope 1200 in this embodiment is a distal viewing scopewith a wide distal viewing area of about 150-170 degree range so thepolyp C and surrounding area can be visualized. After placement of thescope 1200 adjacent the target issue, i.e., slightly proximal of thetarget polyp C, the system 1100 is further advanced over the endoscope1200. Distal coupler (cap) 1148 has an opening 1148 a, and proximalcoupler (cap) 1140 has an opening communicating with the lumen 1116(FIG. 16 ) of the catheter 1110 to enable such backloading of theendoscope 1200 and advancement of the system 1100 thereover. Thecatheter 1110 is advanced over the endoscope 1200 as shown in FIG. 14until it reaches the target site as shown in FIG. 15 , with theretractor system 1050 aligned with the polyp C. As can be appreciated,in this insertion position of the catheter 1110, the retractor system1150 is in the non-expanded (or collapsed) position, with retractorelements 1152, 1154, preferably not exceeding, or only slightlyexceeding, the transverse dimension of the catheter 1110. In thisposition, the retractor elements, or at least retractor elements 1156,1158, are covered by the covering 1170. As shown, in this position, thedistal end 1202 of the endoscope 1200 is preferably positioned at theend of proximal coupler 1140 and does not extend into the working space1151 to thereby leave more room for maneuvering of the endoscopicinstruments within the working space. Other positions, however, are alsocontemplated, e.g., in some versions the endoscope can extend into theworking space 1151. Note also in this insertion position, actuators 1134and 1132 are in their retracted position as shown in FIG. 16 .

Next, to rigidify the retractor system 1150, the actuator 1134 is moveddistally from the position of FIG. 17A to the position of FIG. 17B (seealso the arrow in FIG. 16 ) to advance rigidifying structure 1162 fromthe retracted position to an advanced position within lumen 1165 offlexible tube 1160. This stiffens/stabilizes the retractor system 1150as discussed above. Note, as discussed above, the retractor system 1150can alternatively be stiffened/stabilized by advancement of arigidifying structure over the flexible element as shown in FIGS. 17Cand 17D.

The retractor system 1150 is now expanded. Actuator 1132 is advanceddistally from the position of FIG. 20A to the position of FIG. 20B (seealso FIG. 19 ). This advances block 1146 (which is operably coupled toretractor elements 1152 and 1154 as discussed above) which forcesretractor elements 1152, 1154 laterally outwardly to the position ofFIG. 20B, thereby creating the asymmetric working space (chamber) asdescribed in detail above.

Next, tool channels 1122, 1124 are inserted through the ports 1115, 1117in the proximal region of the catheter 1110 (see FIG. 19A) and advancedby the user through the catheter lumens 1112, 1114 so they extend outthe distal openings of the lumens 1112, 1114 and into the chamber 1151as shown in FIG. 21A. Note as they emerge from the lumens 1112, 114, andout of the confines of the lumen walls of the catheter 1110, theirdistal tips 1122 a, 1124 a return to their curved (bent) position,curving upwardly (as viewed in the orientation of FIG. 21A) toward thepolyp C. Note in FIG. 21A, the retractor elements are first expanded,followed by insertion of the tool channels 1122, 1124 out of thecatheter lumens 1112, 1114 and into the working space 1151. However, itis also contemplated that in an alternative embodiment, the toolchannels 1122, 1124 can be inserted through the catheter lumens 1112,1114 and into the working space 1151 prior to expansion of the retractorelements 1152, 1154. This alternate method is shown in FIG. 21B, withthe tool channel tips 1122 a, 1122 b exposed, but the retractor system1150 still in the non-expanded position. Note the tool channels 1122,1124 can be independently rotated and/or moved axially to adjust theirposition with respect to the polyp C. As can be appreciated, the termsupwardly and downwardly as used herein refer to the orientation of thesystem in the referenced Figures. If the position of the system changes,the orientation and terms would also change.

After insertion of the tool channels 1122, 1124, endoscopic instrument(tool) 1210 is inserted through the luer fitting 1129 (FIG. 19A) of thetool channel 1124 and advanced through the lumen (channel) of the toolchannel. As shown in FIG. 22 , a first endoscopic instrument 1210extends from tool channel 1124 and follows the curve of the tool channel1124. A second endoscopic instrument (tool) 1220 is inserted through theluer fitting 1127 of tool channel 1122 and advanced through the lumen ofthe tool channel 1122. As shown in FIG. 23 , the second endoscopicinstrument follows the curve of the tool channel 1122. As noted above,the tool channels can include a valve, such as the hemostatic valves asshown in FIG. 19B, so insufflation is not lost during insertion andremoval of the endoscopic instruments from the tool channels. Theendoscopic instruments 1210, 1220 can be moved further axially as shownin FIGS. 24 and 25 to extend further from the tool channels 1122, 1124to contact and treat, e.g., remove, the polyp C. This movement of theendoscopic instruments shown by comparing FIGS. 23-25 shows theadvantage of the tool channels 1122, 1124. As can be seen, once the toolchannels 1122, 1124 are in the desired position with respect to thepolyp C, they can be considered as defining a fixed curve. This meansthat when the endoscopic instruments 1210, 1220 are axially advanced,they move closer to the target polyp C, without a change in curvatureand without a change in their axial position with respect to the polypC, thus providing an extra degree of freedom. The endoscopic instrument1210, which in the illustrated embodiment is a grasper, applies tensionon the polyp C while the electrosurgical dissector 1180 dissects/seversthe polyp C from the colon wall B. Other endoscopic instruments forpolyp removal can also be utilized. Additionally, in some embodiments, asingle tool channel can be utilized and another endoscopic instrument,e.g., a grasper or a dissector, can be inserted through a workingchannel (lumen) of the endoscope. Such instrumentation inserted throughan endoscope can also be utilized with the embodiments having two ormore tool channels.

Also note that due to the angles of the tool channels 1122, 1124 andthus the endoscopic instruments inserted therethrough, tissuetriangulation can be achieved as depicted by the dotted lines in FIG. 30.

After removal of the polyp C from the colon wall B, it is placed withinthe cover 1170 as shown in FIG. 26 , ready for removal from the body.Actuator 1134 can be moved proximally to return the retractor system tothe more flexible condition if desired. Actuator 1132 is movedproximally in the direction of the arrow of FIG. 27 to return theexpanded retractor elements 1152, 1154 to their collapsed position ofFIG. 28 for removal of the catheter 1110. The string or suture 1172 isthen tensioned to close the cover (bag) 1170 as shown in FIG. 29 ,forming a bag to encapsulate the polyp C. The switch 1175 can then bemoved to the position of FIG. 31B to lock the string 1172 and therebymaintain the cover 1170 in the closed position. Catheter 1110 is thenremoved from the colon B with the polyp C protected (encapsulated)within the cover 1170. Note that the cover 1170 is preferablytransparent so that the drawings illustrate the retractor elements,bridge members, beam, etc. However, to facilitate understanding of thecover 1170, FIG. 29 shows the retractor elements, bridge elements, beametc. in phantom insider the bag/cover 1170.

FIGS. 32-42 illustrate alternative embodiments of the system of thepresent invention. The system includes floating (flexible) channelswithin the outer tube. In one embodiment, the floating channels arefixed at their proximal and distal ends; in another embodiment thefloating channels are fixed at their proximal ends but are unattached attheir distal ends. As can be appreciated from the discussion below, thefloating channels reduce the overall stiffness of the catheter (outertube) which would otherwise be stiffer if the channels were fixed alongtheir entire length and did not float within the catheter. The floatingchannels also reduce kinking of the tool channels (flexible guides)inserted through the floating channels and reduce kinking of the toolsinserted through the tool channels (or inserted directly through thefloating channels in the embodiments where the tool channels are notutilized).

More specifically, in the embodiment shown in FIGS. 32-34 , the system1210 includes a flexible catheter or outer tubular member (main tube)1212. The proximal portion of the outer tube 1212 is designatedgenerally by reference numeral 1214 and the distal portion is designatedgenerally by reference numeral 1216. A proximal end cap 1218 ispositioned over distal portion 1216 of outer tubular member 1212.

A handle housing 1251 similar to handle housing 1130 of FIG. 11described above is composed of two half shells 1251 a, 1251 b attachedtogether. Shell 1251 b has an actuator 1252 in the form of a slidingbutton, although other forms of actuators can be provided. Actuator 1252is connected to cage wire push tubes, such as push tubes 1428, 1430 ofFIGS. 40 and 42 described below, extending through outer tube 1212.Distal movement of the actuator 1252 along slot 1254 causes distalmovement of the push tubes 1428, 1430 which causes the flexible elementsof the cage to bow outwardly as described below. At the distal end ofthe handle housing 1251 are access ports 1258 a, 1258 b for inflow tubes(not shown) which can be part of a member (organizer) secured within thehandle housing 1251 at a proximal region. At the proximal end of thehandle housing 1251 is a handle end cap 1253 with an opening 1262 forentry of an endoscope into the outer tube 1212. Ports 1248, 1250 extendfrom proximal end cap 1253 to provide entry for the tool channels(flexible guides) 1270, 1271. The ports 1248, 1250 preferably include avalve to maintain insufflation when the tool channels 1270, 1271 areinserted therethrough and translated axially therein. Markings 1264 canbe provided on the handle housing 1251 to indicate to the user theextent of distal travel of the actuator 1252 to control the size of theexpanded cage. For example, the markings provided can be “4, 5 and 6” toindicate expansion of the cage to 4, 5 or 6 centimeters, providing theuser with a general indication of the incremental expanded positions.Other markings and/or extent of expansions are also contemplated. Theactuator 1252 can have a plurality of teeth or other retention structureto retain the actuator 1252 and thus the retractor elements in selectextended positions.

Actuator 1256 on shell 1251 a provides for rigidifying the cage byrigidifying a flexible beam. As described below, in alternateembodiments, a separate slidable beam for rigidifying the cage is notprovided as alternative rigidifying structure is provided. As in theembodiment of FIGS. 17A and 17B, in this embodiment of FIG. 33 , astiffener member in the form of a rigid beam is operatively connected toactuator 1256 so that distal movement of the actuator 1256 advances thestiffener distally either within a lumen of the flexible element or overthe outer surface of the flexible element to provide a stifferstructure. Actuator 1256 can be moved proximally to unstiffen theflexible element to facilitate collapse of the retractor system.

With reference to the cross-sectional view of FIG. 37A, the outer tube(catheter) 1212 in this embodiment has a single lumen 1213. This lumen1213 is dimensioned to receive 1) an endoscope 1200, such as theendoscopes described above; and 2) two flexible channels 1222, 1224. Thetwo flexible channels 1222, 1224 are in the form of flexible tubes andfloat inside the lumen 1213. That is, the two floating channels 1222,1224 have intermediate portions that can move radially (laterally)within the lumen 1213 of the outer tube 1212. Stated another way, thefloating channels 1222, 1224 are unconstrained within the outer tube1212 so they can bend relative to the outer tube 1212 so their bendingaction does not need to follow that of the outer tube 1212. In thismanner, when the outer tube 1212 is inserted in the body lumen and needsto bend to accommodate the curvatures of the body lumen, e.g., thegastrointestinal tract, the flexibility of the outer tube 1212 ismaintained since the floating channels 1222, 1224 can move within thelumen 1213. As can be appreciated, if the two channels were fixed withrespect to the outer tube 1212 so there was no bending or movement withrespect to the outer tube 1212, and the channels were forced to bend inconformity with the outer tube 1212, the outer tube 1212 would be muchstiffer as the channels would have to carry the bending stresses whichcould limit bending of the catheter and/or cause kinking of the toolchannels or tools extending through the channels of the catheter. Thus,in the embodiments of the present invention which include the floatingchannels, these advantages of increased flexibility are achieved. Itshould be understood that any of the systems disclosed herein could beprovided with floating channels. Likewise, any of the systems disclosedherein could be provided without floating channels. FIG. 37B provides byway of example a location of the floating channels 1222, 1224 when theyare moved within the catheter 1212 as it is bent. Clearly, floatingchannels 1222, 1224 will move to various other positions in response tocatheter bending.

Also, by providing a single lumen in this embodiment to receive theendoscope and the tool channels, rather than separate lumens which wouldrequire additional wall structure, a smaller diameter catheter can beprovided which also reduces the overall stiffness of the catheter.

The endoscope 1200 in the embodiment of FIG. 37A also floats within thelumen 1213. That is, the endoscope occupies only a certain region of thelumen 1213 and can move radially (laterally) within the lumen 1213 ofouter tube 1212 to increase the flexibility of the system. Thus, theendoscope 1200 can move relative to the outer tube 1212 in a similarmanner as the floating channels 1222, 1224 can move relative to theouter tube 1212.

In one embodiment by way of example, the internal diameter of the lumen1213 of the outer tube 1212 ranges between about 5 mm and about 50 mmand is preferably about 10 mm to about 20 mm. Each of the floatingchannels preferably has an outer diameter of about 2 mm to about 10 mm,and preferably about 5 mm. The endoscope typically has a diameter ofabout 2 mm to about 20 mm and is preferably about 5 mm to about 12 mm.Thus, as can be appreciated, the floating channels and endoscope occupyonly a small percentage of the internal lumen 1213, leaving sufficientroom for movement. Note that other dimensions and thus ratios of thefloating channels and endoscope to the internal diameter of the lumen1213 are also contemplated for the systems disclosed herein.

In one embodiment, by way of example, the outer tube 1212 has a length,measured from the distal end of handle 1251 to a distal edge of end cap1218 of about 10 cm to about 200 cm, and more preferably about 60 cm toabout 90 cm. The floating channels 1222, 1224 have a length of about10.1 cm to about 204 cm, and preferably about 60.5 cm to about 91 cm,thereby exceeding the length of the outer tube 1212. Other dimensionsare also contemplated. This greater length of the floating channels1222, 1224 in the embodiments where they are fixed at both the proximaland distal ends enables the floating movement.

Turning now to details of the floating channels and their securementwithin outer tube 1212, in the embodiment of FIGS. 32-34 , channel 1222,referred to herein as a first flexible channel or a first floatingchannel or a first flexible tube, has a proximal end 1238 and anopposing distal end 1239. Channel 1224, referred to herein as a secondflexible channel or a second floating channel or a second flexible tube,has a proximal end 1246 and an opposing distal end 1249. Note the terms“first” and “second” to describe various components of the systems ofthe present invention are used herein for ease of description. Note inthe embodiments of FIGS. 32-42 , two floating channels are provided. Itis also contemplated that only one floating channel is provided or morethan two floating channels are provided.

Positioned with the outer tube 1212 at a distal end is a first fixeddistal tube 1226 which forms a pocket for the first floating channel1222. First distal tube 1226 has an opening 1227, a proximal edge 1236and a distal edge 1237. In some embodiments, instead of an opening 1227the distal end can be closed. Preferably, distal edge 1237 issubstantially flush with the distal edge of distal end cap 1218. At theproximal end of the system, positioned either within the outer tube 1212or alternatively at a distal region of the handle housing 1251, is afirst fixed proximal tube 1228.

Also positioned with the outer tube 1212 at a distal end is a secondfixed distal tube 1230 which forms a pocket for the second floatingchannel 1224. Distal tube 1230 has an opening 1231, a proximal edge 1242and a distal edge 1243. In some embodiments, instead of an opening 1231the distal end can be closed. Preferably, distal edge 1243 issubstantially flush with the distal edge of distal end cap 1218. At theproximal end of the system, positioned either within the outer tube 1212or alternatively at a distal region of the handle housing 1251, is asecond fixed proximal tube 1232 having a proximal edge 1246. The firstand second proximal tubes 1228, 1232 are preferably attached to an innerwall of the outer tube 1212 or handle housing 1251 by bonding or weldingor other attachment methods. Similarly, the first and second distaltubes 1226, 1230 are preferably attached to an inner wall of the outertube 1212 by bonding or welding or other attachment methods. Note inFIG. 33 , the fixed proximal tubes 1228 or 1232 are shown cutaway (intoa half cylinder) for clarity, it being understood that the tubes can becylindrical in configuration like the distal fixed tubes 1226, 1230.Other configurations for the fixed distal and proximal tubes arecontemplated.

The distal end of the first flexible channel (tube) 1222 is positionedwithin the first fixed distal tube 1226 and secured thereto such as bybonding or welding or other attachment methods. It can terminate in anyfixed position within the distal tube 1226, and in the illustratedembodiment, terminates at the distal end of the distal tube 1226. Theproximal end 1238 of first flexible channel 1222 is positioned withinthe first fixed proximal tube 1228 and secured thereto such as bybonding or welding or other attachment methods. It can terminate in anyfixed position within the proximal tube 1228, and in the illustratedembodiment, terminates at the proximal end of the proximal tube 1228. Inthis manner, the first flexible channel 1222 is fixed with respect tothe outer tube 1212 at its proximal end and at its distal end. However,it remains unattached in an intermediate portion between the proximaland distal end, e.g., along its length between its two fixed ends, so itcan float within the outer tube 1212. Similarly, the distal end of thesecond flexible channel (tube) 1224 is positioned within the secondfixed distal tube 1230 and secured thereto such as by bonding or weldingor other attachment methods. It can terminate in any fixed positionwithin the distal tube 1230, and in the illustrated embodiment,terminates at the distal end of the distal tube 1230. The proximal endof second flexible channel 1224 is positioned within the second fixedproximal tube 1232 and secured thereto such as by bonding or welding orother attachment methods. It can terminate in any fixed position withinthe proximal tube 1232, and in the illustrated embodiment, terminates atthe proximal end of the proximal tube 1232. In this manner, the secondflexible channel 1224 is fixed with respect to the outer tube 1212 atits proximal end and at its distal end. However it remains unattached inan intermediate portion between the proximal and distal end, e.g., alongits length between its two fixed ends, so it can float within the outertube 1212.

First and second flexible guides or tool channels 1271, 1270 (FIG. 33 )are inserted through ports 1248 and 1250 in the same manner as flexibleguides (tool channels) 1122, 1124 of FIG. 19A. The flexible guides 1271,1270 extend through floating channels 1222, 1224, respectively, toemerge out the distal ends into the chamber. Note flexible guides 1271and 1270 can in some embodiments be composed of a Pebax tubing, anoverlying PVC tubing and polyolefin shrink tubing over the PVC tubing.The other flexible guides disclosed herein can also be composed of suchstructure. This provides a balance between flexibility and rigidity, andalso beefs up the proximal end to facilitate handling by the user. Notethe flexible guides 1271, 1270 emerge from the proximal cap 1218 andbend at their distal tips in the same manner as flexible guides (toolchannels) 1122, 1124. Therefore, since the flexible guides 1271, 1270are identical in function for guiding/bending working instrumentsinserted therethrough, for brevity they will not be discussed furthersince the discussion of flexible guides 1122, 1124 above is fullyapplicable to flexible guides 1271, 1270. Note for clarity the flexibleguides are not shown in the other Figures, it being understood that theywould function in the manner of FIGS. 21-25 .

In an alternate embodiment of FIGS. 35A-35C, the floating (flexible)channels are fixed at their proximal end but remain free (unattached) attheir distal ends. More specifically, FIGS. 35A-35C illustrate a cutawayview of the system so that only one of the floating channels, the secondfloating channel 1324, is illustrated. The first floating channel isattached and configured in a similar fashion as second floating channel1324. Second floating channel 1324 is attached at its proximal end inthe same manner as floating channel 1224, i.e., attached within a fixedproximal tube. The first floating channel 1322 is not shown in FIGS.35A-35C but is shown in FIG. 38 and is attached at its proximal end inthe same manner as first floating channel 1222, i.e., attached within afixed proximal tube. The floating channels 1322, 1324 differ from thefloating channels 1222, 1224 of FIG. 32 in that they are unattached attheir distal ends. Consequently, the floating channels 1322, 1324 formtelescoping channels within the outer tube (or catheter) 1312.

More specifically, with continued reference to FIGS. 35A-35C and FIG. 38, a first fixed distal tube 1326 is attached within the outer tube 1312adjacent proximal end cap 1318 positioned over the outer tube (catheter)1312 of the system 1310. First fixed distal tube 1326 forms a pocket forthe first floating channel 1322. Distal tube 1326 has a lumen extendingtherethrough, a proximal edge 1325 and a distal edge 1329. Preferably,distal edge 1329 is substantially flush with the distal edge of proximalend cap 1318. A second fixed distal tube 1330 is attached within outertube 1312 adjacent the proximal end cap 1318 and forms a pocket for thesecond floating channel 1324. Distal tube 1330 has a lumen 1331extending therethrough, a proximal edge 1333 and a distal edge 1338.Preferably distal edge 1338 is substantially flush with the distal edgeof proximal end cap 1318. Second floating channel 1324 has a distal end1337 which in the position of FIG. 35A is fully within the second fixeddistal tube 1330. Upon bending of the outer tube 1312 in one direction,the second floating channel 1324 moves distally to the position of FIG.35B. Upon additional bending, the floating channel 1324 can extendbeyond the distal edge 1338 of the second fixed distal tube 1330 (andbeyond the distal edge of the proximal end cap 1318) as shown in FIG.35C. FIG. 38 (and FIG. 39B) illustrates the effect in bending of theouter tube 1312 in the opposite direction of FIG. 35C. As shown, thesecond floating channel 1324 remains within the lumen 1331 of the secondfixed distal tube 1330 while the distal end 1327 of first floatingchannel 1322 extends distally beyond the distal edge 1329 of first fixeddistal tube 1326 (and beyond the distal edge of the proximal end cap1318).

Stated another way, the floating channels 1322, 1324 are unconstrainedwithin outer tube (catheter) 1312 and take the shortest path when theouter tube 1312 is bent. Thus, the movement readjusts their position toadjust for the length difference on bending of the outer tube 1312. Notethe floating channels 1322, 1324 can also slightly rotate during bendingof the outer 1312 to compensate for stress applied to the floatingchannels during bending. Consequently, this prevents the eccentricpositioned channels from being stretched on the outer portion of thecurvature and buckling on the inner portion of the curvature. Thefloating channels can move around within lumen 1315 of outer tube 1312and take any shape to accommodate bending to increase the flexibility ofthe device.

Note that in FIG. 35C the outer tube 1312 is bent in a first directionso that second floating channel 1324 on the inside curvature of theouter tube 1312 is advanced distally beyond distal tube 1330. In FIG. 38, the outer tube 1312 is bent in a second opposite direction so that thefirst floating channel 1322 on the inside curvature of the outer tube1312 extends beyond the distal tube 1326.

The fixed distal tubes 1326, 1330 which form pockets for the respectivefloating channels 1322, 1324 are dimensioned so their length exceeds thelargest extent of movement in response to the greatest curvature of theouter tube 1312 as a result of bending of the outer tube 1312 duringuse. This ensures that the floating channels 1322, 1324 will not retractout of the proximal end of the respective fixed distal tubes 1326, 1330,In a preferred embodiment, the length of the distal tubes 1326 and 1330are between about 1.5 cm to about 3 cm, and preferably about 2 cm. Otherdimensions are also contemplated.

Flexible guides identical to flexible guides 1270, 1271 of FIG. 33and/or flexible guides 1122, 1124 of FIGS. 19-25 are inserted throughthe floating channels 1322 and 1324 in the same manner as describedabove so that endoscopic working instruments can be inserted into thechamber formed by the flexible elements for performing the procedure.Note, alternatively, endoscopic working instruments can be inserteddirectly through the floating channels of any of the embodiments hereinwithout the intermediary flexible guides. Such direct insertion ofinstrumentation without flexible guides (tool channels) is alsodescribed above as an alternative system and method.

The working instruments can include graspers for example. Adissecting/cutting instrument can be inserted through the flexible guidein the floating channel, or alternatively inserted through a workingchannel of the endoscope. Thus, various working instruments can beinserted through the flexible channels and endoscope channel(s).

The flexible guides described herein, e.g., flexible guides 1270, 1271,can be color coded to improve the system's usability. For example,flexible guide 1270 can be of a first color, such as red, and flexibleguide 1271 can be of a second color, such as black. In this way, whenthe user is manipulating the flexible guides 1270, 1271 at theirproximal ends outside the patient's body, the user will more readily seethe corresponding color coordinated tip being manipulated within theexpanded cage. Note the entire flexible guide can have the same color oralternatively the matching color can be only at the proximal end visibleto the user and the distal end visible by the endoscope. It should alsobe appreciated, that instead of color coding, other indicia can beprovided so the user can match the proximal end of the flexible tubewith the distal end within the chamber.

FIGS. 39A-39C illustrate the distal portion of the system 1310 to showthe retractor elements in the expanded configuration to form theasymmetric cage to create a working space for the surgical procedure.The retractor system 1370 is identical to the retractor system 1150 ofthe embodiment of FIG. 21A and therefore when expanded from itscollapsed insertion position forms a working space expanding system andin certain surgical procedures a body lumen reshaping system whichreshapes the body lumen to form an asymmetric space to increase theworking space for the maneuverability of the endoscopic instrumentsthrough the flexible guides of the system. That is, the retractor systemcreates a self-contained “surgical suite” which forms an expanded areawithin the body lumen for the surgeon to perform the surgical procedurewithin the created space. By reshaping the body lumen, the working spaceis maximized without overstretching the body lumen. Such working spacemaximization increases the distance between the target tissue and theend effectors of the endoscopic instruments, hence improvingmaneuverability of the instruments during the surgical procedure. Notethe flexible tool channels (flexible guides) and endoscopic instrumentsare not shown in these drawings for clarity but would operate in thesame manner as in FIGS. 21-25 . The retractor system of system 1210 ofFIGS. 32 and 33 is identical to the retractor system 1370 of system 1310and therefore the discussion of the structure and function of theretractor system 1370 is fully applicable to the retractor system ofsystem 1210. FIG. 36 discussed below illustrates an example of thereshaping of the body lumen to a more oval-like configuration.

As noted above, retractor system 1370 is identical to retractor system1150 and includes flexible retractor elements 1380, 1382 which createthe working chamber (space) within the body lumen and form an asymmetriccage. Flexible retractor elements 1384, 1386 form the base of theretractor system 1370. Movement of the retractor elements 1380, 1382,1384 and 1386 is the same as retractor elements 1152, 1154, 1156 and1158 described above and/or the same as movement of the retractorelements of FIGS. 40-42 described below. The retractor system 1370, alsolike retractor system 1150, can include a bridge member 1390 spanningretractor elements 1380,1382 and optionally a bridge member 1392spanning retractor elements 1384, 1386, which are configured andfunction in the same manner as aforedescribed bridge members 1155, 1157and therefore for brevity are not described herein again in detail asthe description above for bridge members 1155, 1157 and theiralternatives are fully applicable to the retractor system 1370.

The retractor elements 1380, 1382, 1384, 1386 can be made ofsubstantially flexible materials and are preferably formed of a wirecomposed of nitinol. A layer of soft compatible material, but preferablyPTFE tubing 1387, can be positioned over a portion of the wires. Apolyolefin heat shrink 1389 can be positioned over the retractor portionof the elements and bridge member to retain the bridge members. Note theretractor elements angulate at the distal end, i.e., pivot from thedistal cap 1374. To bulk up the retractor elements adjacent this region,a covering material such as the PTFE tubing can be provided.

Flexible tube or beam 1391 in the form of a rod or tube has a lumen toreceive a stabilizing or rigidifying structure such as rigid tube or rod1393. (Alternatively, the rigid tube or rod can be slid over beam 1391).Flexible beam 1391 and rigidifying structure 1393 are identical toflexible beam 1160 and rigid beam 1162 of FIGS. 17A, 17B describedabove. Therefore, for brevity, further details of these components arenot provided herein since the structure and function of the beams 1160,1162 provided in detail above are fully applicable to the beams 1391,1393. An actuator like actuator 1256 of FIG. 33 is operably connected tothe rod 1393 for sliding movement with respect to beam 1391 to increasethe rigidity of the cage. Alternative structure for the rigidifyingstructure described above, such as sliding a rigidifying structure overa flexible beam, are also fully applicable as alternatives to therigidifying structure of the retractor system 1370 of FIG. 39A and theretractor system of the system 1210 of FIGS. 32 and 33 .

A covering or cover 1378 identical to cover 1170 of FIGS. 28 and 29 ofFigure is provided. The cover 1378 covers the retractor elements 1380,1382, 1384, 1386 and in the expanded position of the retractor system1370 has an opening 1395 for access to the tissue. Further details ofthe cover 1395 are not provided herein since the cover 1395 is identicalin structure and function to cover 1170. Also, the various embodimentsof the covers described above are fully applicable to the cover for thesystems of FIGS. 32-42 .

In alternate embodiments, the pursestring to close the cover 1378 ofFIGS. 32-42 or the cover of any over the aforedescribed covers iseliminated and reliance is on the cover itself. Elimination of thepursestring simplifies the device by providing fewer components andreduces the steps in the surgical procedure. In embodiments without thepursestring, when the tissue, e.g., the severed polyp, is pulled intothe cage formed by the retractor elements, and the retractor elementsreturn to their non-expanded position to collapse the cage, the covercloses down on the captured tissue, e.g., the polyp, to prevent orminimize seeding of the pathological tissue, e.g., cancerous tissue,during removal. The grasper can also maintain its grip on the severedtissue so the grasped tissue and catheter are removed together from thebody lumen. The target tissue, e.g., polyp, during the procedure andduring its removal from the body would typically be located inside thecage and practically isolated by the cage and its cover from thesurrounding innocent tissues.

FIGS. 40-42 illustrate an alternative retractor system of the presentinvention. The retractor system 1415 of system 1410 is identical to theretractor system 1370 FIG. 39A (and system 1150 of FIG. 17C) except forthe rigidifying structure. In this embodiment, instead of a movable beamto stiffen an otherwise flexible element, an element of the retractorsystem has inherent stiffness characteristics to stiffen the overallretractor system 1415. More specifically, retractor system 1415 hasflexible retractor elements 1412, 1414 which expand (bow outwardly) toform the chamber (cage) to create the working space in the same manneras retractor elements 1380, 1382 described above. These flexibleelements 1412, 1414 are expanded by movement of actuator 1416 in thesame manner that movement of actuator 1252 (FIG. 33 ) expands flexibleretractor elements 1380, 1382. That is, actuator 1416 is attached toblock or carriage 1426 which contains a slot or opening for attachmentof push cable 1428. Push cable 1430 is also attached within another slotor opening of block 1426. Thus, push cables 1428, 1430 are operativelyconnected at their proximal ends to actuator 1416. A connection tube1432 connects push cable 1428 to flexible element 1414 and connectiontube 1434 connects push cable 1430 to flexible element 1412. Theconnection tubes 1432, 1434 are at the distal end of the outer tube 1411at the region of the proximal cap 1413. More specifically, a distal endof push cable 1428 is secured within connection tube 1432 and a proximalend of flexible retractor element 1414 is secured within connection tube1432. A distal end of push cable 1430 is secured within connection tube1434 and a proximal end of flexible retractor element 1412 is securedwithin connection tube 1434. Slidable advancement of actuator 1416within slot 1436 of handle housing 1438 moves push cables 1428, 1430,distally which bows flexible elements 1412, 1414 outwardly to anexpanded position due to their attachment at distal end cap 1417.Markings 1440 can be provided to indicate retractor element expansion asin FIG. 33 .

Retractor system 1410 also has flexible elements 1418, 1420 forming thebase of the cage and identical to retractor elements 1384, 1386described above. Retractor system 1415, however, differs from retractorsystem 1370 (and 1150) in that a beam 1422 is provided which itself hassufficient rigidity to maintain the overall stiffness of the expandedcage when fairly mild forces are applied (e.g., weight of small portionof the intestinal wall, minor external intra-abdominal pressure, etc.)and limit bending of the cage with respect to the outer tube 1422 duringuse when fairly mild forces are applied. That is, the beam 1422extending from the proximal cap 1413 to the distal cap 1417 maintainsthe rigidity of the system when fairly mild forces are applied as it isfixed at both ends and extends the length of the expanded cage. Therigidity of the beam 1422, however, is optimized to be sufficientlyflexible when fairly significant force is applied to it (e.g., bendingforce of the endoscope). This rigidifying of the beam can be achieved inseveral ways. In some embodiments, the wire element which forms therigidifying beam itself is sufficiently rigid to achieve the stabilityof the expanded cage. However, to further increase the rigidity, butpreserve the desired flexibility, the rigidifying beam in alternateembodiments can have an increased thickness to further optimize thebending of the cage's elements such as beam 1422. As shown, in thisembodiment, the diameter or (cross-sectional dimension if a non-circularbeam is used) is greater than the diameter (or cross-sectional dimensionif non-circular elements are used) of the flexible elements 1412, 1414,1418, and/or 1420. In other embodiments, the rigidifying beam can becomposed of a stiffer material than one or more of the other flexibleelements. Such stiffer materials can include for example steel orplastic.

Note the flexible tool guides (tool channels) are not shown in FIGS.40-42 for clarity, but flexible guides such as flexible guides 1270,1271 of FIG. 33 can be utilized. Also, in this embodiment only a singleactuator is provided for expansion of the retractor system 1415 since anactuator for rigidifying the structure is not necessary.

In all other respects, system 1410 is identical to system 1310.

FIGS. 43A-47C illustrate alternate embodiments for stabilizing thechamber. In these embodiments, a distally positioned expandablestabilizing structure is provided which stabilizes the distal portion ofthe catheter. As can be appreciated, one way to enhance stabilization isto fix the distal point of the chamber so that when the flexibleelements forming the chamber are pushed forward, the flexible elementsbulge to the side as the fixated distal point doesn't deviate to therebyprovide support for the flexible elements. In the foregoing embodiments,this distal fixation is achieved by an elongated stabilizing rod whichcan be fixed relative to the catheter or can be selectively rigidifiedto form a more rigid beam by a rigidifying member slid thereover ortherein as described in detail above. In the embodiments of FIGS.43A-47C, the stabilization is achieved by an expanding stabilizingmember at the distal end which selectively expands to fit the transversedimension of the body space, e.g., the colon. In some embodiments, theexpanding stabilizing member is axially fixed adjacent to or over adistal coupling structure for the flexible elements; in otherembodiments the expanding stabilizing member is movable axially to aposition adjacent or over the distal coupling structure. Additionally,in some embodiments, the expanding stabilizing member is an inflatableballoon; in other embodiments, the expanding stabilizing member is amechanical structure such as a mesh or stent-like structure. Each ofthese variations is discussed in detail below.

As can be appreciated, in order to advance the catheter through theanatomy to the target site, sufficient flexibility is necessary. On theother hand, sufficient rigidity, i.e., distal fixation of the catheter,is required to bend the flexible elements and to maintain the chamberand thus the working space for treating the target tissue. Theembodiments of FIG. 43A-47C provide an approach to achieving this byproviding fewer flexible elements than in the forgoing embodiments tothereby reduce the overall rigidity of the catheter while providing anexpandable stabilizing structure at the distal end that can be collapsedand flexible for insertion and selectively expanded to rigidify andstabilize the system when the catheter is at the desired surgical site.

Note in the embodiments of FIGS. 43A-47C, the flexible elements areidentical as are other components of the flexible catheter and system.Therefore, for ease of understanding, these like components in FIGS.43A-47C, even though they disclose different stabilizing elements, areprovided with the same reference numerals throughout the drawings.However, where these embodiments differ, e.g., the expandablestabilizing member, different reference numerals are utilized for easeof understanding the differences.

Turning first to the embodiment of FIGS. 43A-43D, system 1500 includes amulti-lumen catheter or tubular member 1510 configured to receive one ormore tool channels or flexible instrument guides. FIG. 43C shows twotool channels 1122 and 1124 (identical to the aforedescribed toolchannels 1122, 1124), it being understood that in some embodiments, onlyone tool channel can be utilized and in other embodiments more than twotool channels can be utilized, with the catheter provided with asufficient number of lumens. The tool channels 1122, 1124 can bepackaged as a kit with the catheter 1510 in the same manner as shown inFIG. 11 . Alternatively, the tool channels 1122, 1124 can be packagedseparately. In other embodiments, the tool channels are packaged alreadyinside the lumens of the catheter 1510. Each tool channel 1122, 1124 hasa lumen (channel) to receive an endoscopic instrument (tool)therethrough, such as the endoscopic instruments described above. Thetool channels 1122, 1124 can be provided as floating channels within alumen of the catheter as described in detail above.

The retractor system 1550, which forms a working space expanding system,and in certain clinical applications, a body lumen reshaping orreconfiguring system, is positioned at the distal portion 1511 ofcatheter 1510 in the same manner as the retractor system 1150 ispositioned at the distal portion 1111 of the catheter 1110 describedabove. The retractor system 1550 of catheter 1510 includes two flexibleretractor elements 1552 and 1554, although in alternate embodiments,additional flexible elements could be provided. Retractor elements 1552,1554 form the expandable elements which create the working chamber(space) within the body lumen and form an asymmetric cage. Retractorelements 1552, 1554 are expandable to form an asymmetric working chamberto improve visibility and working space as described in detail abovewith respect to the other systems forming asymmetrical working spaces.Note retractor system 1510 differs from retractor system 1150 in thatonly two retractor elements extend from the proximal coupler 1540.

As in retractor elements 1152 and 1154, retractor elements 1552 and 1554move from a collapsed insertion position wherein they preferably do notextend beyond, or significantly beyond, the transverse dimension of thecatheter 1510 to an expanded position wherein they bow laterallyoutwardly beyond the transverse dimension of the catheter 1510. As inthe embodiments described above, the retractor system 1550, i.e., theretractor elements 1552, 1554, expand to only one side of a planepassing through a longitudinal axis of the catheter 1510, therebycreating the asymmetric working space 1551 (and asymmetric cage), withits attendant advantages described herein.

Retractor elements 1552, 1554 can have a bridge member 1555 to addstability to the retractor i.e., the flexible retractor elements, duringbending and maintain a desired orientation of the retractor elementsduring the expansion i.e., to facilitate controlled spaceexpansion/reshaping. The bridge member 1555 is attached to the tworetractor elements 1552, 1554, preferably at an intermediate portion, tocreate a transverse structure for the elements 1552, 1554, limitingside-to side movement. As shown, bridge member 1555 is identical tobridge member 1155 discussed above and therefore for brevity is notdiscussed in detail since the description and function of bridge member1155 is fully applicable to bridge member 1555. Note the bridge member1555 can be a separate component attached to the retractor elements bytubular elements (like tubular elements 1159 a, 1159 b discussed above)which are fitted over and attached to the retractor elements 1552, 1554,respectively. Other methods of attachment of the bridge members are alsocontemplated. Alternately, the bridge member 1555 can be integrallyformed with one or both of the retractor elements 1552, 1554respectively, to add to the stability of the retractor system. Thebridge member 1555 can also include in certain embodiments legs 1555 a,1555 b to provide additional stability similar to the legs 1155 d, 1155e described above.

The catheter 1510 includes a proximal coupler (cap) 1540 through whichthe retractor elements extend in the same manner as proximal coupler1140. Retractor elements 1552, 1554 are fixedly attached at a distal endto coupling structure, i.e., distal coupler or distal nexus 1548 similarto distal coupler 1148. The distal coupler 1548 has openings to receiveretractor elements 1552, 1554 for securement to the coupler 1548 in thesame manner as coupler 1148 described above. The retractor elements1552, 1554 can be moved to the expanded (laterally outward/bowed)position in the same manner as retractor elements 1152, 1152, e.g., by aslidable actuator. Note the proximal and distal couplers 1540, 1548 canhave openings dimensioned to receive an endoscope when the catheter 1510is backloaded over the endoscope as described herein. As describedabove, a plurality of teeth (not shown) similar to the teeth of FIGS.6A-6D can be provided in the housing for engagement by a tooth coupledto the actuator for the flexible elements, thereby forming a retainingor locking mechanism to retain the retractor elements in one of severalselect positions. A release mechanism for the retaining or lockingmechanism can be provided.

Additionally, it should be appreciated that alternative ways to expandthe retractor elements can be utilized, including for example providingrelatively movable couplers 1540, 1548 to expand the retractor elements1552, 1554 in the same manner described in the alternatives above. Theretractor elements can also alternatively be made of self-expandingmaterial, such as shape memory material, which expand when exposed fromthe catheter.

A sheath or covering material 1576 can be placed over the flexibleelements 1552, 1554 for creating an enclosed space for capture andwithdrawal of tissue. This is shown in FIG. 43D. (The covering is notshown in FIGS. 43A-43C for clarity). The covering 1576 can be configuredand function in the same manner as covering 1170 described above so thatthe aforedescribed description of the function and configuration ofcovering 1170, and its alternatives, are fully applicable to covering1576. Note the covering material 1576 can be placed over the flexibleelements in the other embodiments described herein.

An expandable structure (member) 1570 in the form of an inflatableballoon 1572 is positioned distal of the distal coupler 1548. Theballoon 1572 is positioned at a distal end of a catheter 1574 which hasa lumen communicating with the interior of the balloon 1572 forinflation. The catheter 1574 extends through a lumen 1513 in catheter1510 which can be a separate lumen or alternatively a region of thelumen that receives the endoscope and/or a tool channel. In theinsertion position of the catheter 1510, the balloon 1572 is in acollapsed non-inflated position to present a low profile. In theinsertion position, the catheter 1574 is in an extended position, withthe non-inflated balloon 1572 distal of the coupler 1548 (see FIG. 43B).After insertion of the catheter 1510 to the desired position withrespect to the target tissue, the catheter 1574 is retracted proximallywithin the lumen 1513 of catheter 1510 to retract the balloon 1572axially toward the distal coupler 1548. When positioned adjacent thedistal coupler 1548, just distal of the distal end of coupler 1548 andeither slightly spaced or abutting, the balloon 1572 is inflated so theexpanded balloon 1572 fills the transverse dimension within the bodyspace, e.g. colon C, as shown in FIG. 43C. The retractor elements 1552,1552 are moved to the expanded position, bowing outwardly, in the mannerdescribed above, e.g., by movement of an actuator operatively connectedto the retractor elements 1552, 1554 to form the chamber for workinginstruments.

Note that the catheter 1574 and attached balloon 1572 (as in the otherballoon or mechanical expander embodiments described below) can beretracted and positioned adjacent the distal coupler 1548 either beforeor after expansion of the retractor elements 1552, 1554. Also note thatthe balloon 1572 can be inflated either before or after retraction toits proximal position adjacent the distal coupler 1548. Such sequence ofsteps, i.e., axial movement and/or expansion of the expandable memberbefore or after the expansion of the retractor elements can occur in theother embodiments herein.

Note as shown in FIG. 43C, the expanded retractor elements reshape thebody lumen e.g., colon, and the balloon 1572 can be positioned distal ofthe reshaped lumen region, engaging the wall of the lumen to provide afixed and therefore stabilized distal point for the retractor elementsto stabilize the working chamber.

In the alternate embodiment of FIGS. 44A-44C, instead of the balloonretracted adjacent the distal coupler 1548, the balloon 1582 isretracted to overlie the coupler 1548. The expandable stabilizerstructure 1581 of system 1580 includes a donut shape balloon 1582 havingan opening 1586 larger than the transverse dimension (outer diameter) ofthe distal coupler 1548 so it can fit over the distal coupler 1548.Balloon 1582 is attached to the distal end of catheter 1584 which isslidably received in the lumen of the catheter 1510 in the same manneras catheter 1574 described above. The balloon 1582 is positioned at adistal end of a catheter 1584 which has a lumen communicating with theinterior of the balloon 1582 for inflation. The catheter 1584 has a bend1588 to accommodate opening 1586. Note the bend 1588 is shown by way ofexample, it being understood that other angulations, such as a softercurve, smaller angle, etc. can be utilized The system 1580 is the sameas system 1510 except for the stabilizing feature, therefore for brevitythe same features are not described. The inflatable balloon 1582 isinitially positioned distal of the distal coupler 1548. The catheter1584, like catheter 1574, slidably extends through a lumen in catheter1510 which can be a separate lumen or alternatively a region of thelumen that receives the endoscope and/or a tool channel.

In the insertion position of the catheter 1510, the balloon 1582 is in acollapsed non-inflated position to present a low profile for insertion.In this insertion position, the catheter 1584 is in an extendedposition, with the non-inflated balloon 1582 distal of the coupler 1548.After insertion of the catheter 1510 to the desired position withrespect to the target tissue, the catheter 1584 is retracted proximallywithin the lumen of catheter 1510 to retract the balloon 1582 axiallytoward the distal coupler 1548 and over the coupler 1548. Whenpositioned over the distal coupler 1548 such that the distal coupler1548 is seated within opening 1586 in balloon 1582, the balloon 1582 isinflated (or further inflated if partially inflated prior to partial offull retraction) to fill the transverse dimension within the body space,e.g., colon, like the way balloon 1572 fills the space in FIG. 43C).Note alternatively the balloon 1582 can be fully inflated prior toretraction over distal coupler 1548. The retractor elements 1552, 1554are moved to the expanded position, bowing outwardly, in the mannerdescribed above, e.g., by movement of an actuator operatively connectedto the retractor elements 1552, 1554 to form the chamber for workinginstruments. As noted above, the retractor elements 1552, 1554 can beexpanded before or after inflation of the balloon 1582 and before orafter retraction of the balloon 1582.

In the alternate embodiment of FIGS. 45A-45B, instead of the stabilizingstructure, i.e., the balloon, retracted to a position adjacent to oroverlying the distal coupler 1548, balloon 1592 of stabilizer structure1591 of system 1590 is axially fixed in a position overlying the distalcoupler 1548. The balloon 1592 is donut shaped like balloon 1582 havingan internal opening dimensioned to fit over the distal coupler 1548.Balloon 1592 is at the distal end of catheter 1594 which is axiallyfixed within the lumen of the catheter 1510. The interior of the balloon1592 communicates with the lumen in catheter 1594 for inflation of theballoon. The system of FIGS. 45A, 45B is otherwise the same as system1580, therefore for brevity the same features are not repeated herein.In use, the catheter 1510 is inserted with the balloon catheter 1594fixedly positioned therein and the balloon 1592 in the non-expandedposition lying over the distal coupler 1548 as shown in FIG. 45A. Duringthe procedure, the balloon 1592 is inflated via the inflation lumenextending through catheter 1594 and in communication with the ballooninterior to expand the balloon 1592 to the position of FIG. 45B tostabilize the chamber formed by the expanded retractor elements 1552,1554.

FIGS. 46A-47C illustrate alternate embodiments of the stabilizingstructure having a mechanical expander instead of an inflatable balloon.Turning first to FIGS. 46A-46C, in this alternate embodiment, instead ofa balloon retracted adjacent the distal coupler 1548, a mesh structure1602 is utilized to stabilize the chamber. The expandable stabilizerstructure 1601 of system 1600 includes a structure composed of a seriesof wires, fibers or other material formed into a mesh structure withsufficient rigidity to provide a stabilizing structure for the chamber.Mesh structure 1602 is positioned within a distal end of catheter 1604which is slidably received in the lumen of the catheter 1510 in the samemanner as catheter 1574 described above. An actuator 1606, such as apush or pull rod is slidably received within the lumen of catheter 1604and attached to the mesh structure 1602, e.g., at a distal end, toexpand and collapse the mesh structure. The system 1600 is the same assystem 1510 except for the stabilizing feature, therefore for brevitythe same features are not described. The mesh structure 1602 isinitially positioned distal of the distal coupler 1548. The catheter1604, like catheter 1574, slidably extends through a lumen 1513 incatheter 1510 which can be a separate lumen or alternatively a region ofthe lumen that receives the endoscope and/or a tool channel.

In the insertion position of the catheter 1510, the mesh 1602 is in acollapsed non-expanded position to present a low profile for insertion.In this insertion position, the catheter 1604 is in the extended ordistal position of FIG. 46A, with the non-expanded (collapsed) mesh 1602distal of the coupler 1548, i.e., spaced further from the coupler 1548.After insertion of the catheter 1510 to the desired position withrespect to the target tissue, the catheter 1604 is retracted proximallywithin the lumen 1513 of catheter 1510 to retract the mesh structure1602 axially toward the distal coupler 1548 to the position of FIG. 46B.In the illustrated embodiment, the mesh structure 1602 is retractedadjacent the distal coupler 1548, either slightly spaced or in abutment.In alternate embodiments, the mesh structure 1602 has an opening likeopening 1586 of balloon 1582 of FIG. 44B dimensioned to fit over thedistal coupler 1548 so the mesh structure 1602 can be retracted tooverlie the distal coupler 1548. Once retracted, the push/pull rod 1606is pulled axially (or further pulled if partially pulled prior toretraction) to expand mesh 1602 to fill the transverse dimension withinthe body space, e.g., colon, like the way balloon 1572 fills the spacein FIG. 43C. The retractor elements 1552, 1554 are moved to the expandedposition, bowing outwardly, in the manner described above, e.g., bymovement of an actuator operatively connected to the retractor elements1552, 1554 to form the chamber for working instruments. As noted above,the retractor elements 1552, 1554 can be expanded before or afterproximal movement of the mesh structure 1602 toward the distal coupler1548 and before or after expansion of the mesh structure 1602.

Note as an alternative to push/pull rod 1606, the catheter 1604 caninclude a pusher and the mesh 1602 is retained in a collapsed positionwithin the catheter 1604. When the catheter 1604 is moved to the desiredsite, the pusher is advanced distally to force the mesh 1602 out of thedistal end of the catheter 1604 to enable it to automatically expand tothe expanded position of FIG. 46C due to its spring like characteristicsor its shape memory material.

In an alternate embodiment, catheter 1604 is axially fixed withincatheter 1510 and the mesh structure 1602 is therefore axially fixedwith respect to the distal coupler 1548, positioned distally adjacent oroverlying the coupler 1548. Thus, in this embodiment, the mesh 1602 isin this fixed axial position when collapsed and inserted and remains inthe fixed axial position when expanded.

An alternate expandable mechanical stabilizing structure is illustratedin FIGS. 47A-47C. In this embodiment, instead of a mesh structure, astent-like structure 1612 is provided formed by a plurality of strutsinterconnected to form a plurality of geometric shapes. Stent structure1612 is positioned within the distal end of catheter 1614 which isslidably received in the lumen of the catheter 1510 in the same manneras catheter 1574 described above. An actuator 1616, such as a push orpull rod, is slidably received within the lumen of catheter 1614 andattached to the stent structure 1612, e.g. at a distal end, to move thestent structure 1612 between the collapsed and expanded positions. Thesystem 1610 is the same as system 1510 except for the stabilizingfeature, therefore for brevity the same features are not described. Thestent structure 1612 is initially positioned distal of the distalcoupler 1548. The catheter 1614, like catheter 1574, slidably extendsthrough a lumen 1513 in catheter 1510 which can be a separate lumen oralternatively a region of the lumen that receives the endoscope and/or atool channel.

In the insertion position of the catheter 1510, the stent structure 1612is in a collapsed non-expanded position to present a low profile forinsertion. In this insertion position, the catheter 1614 is in theextended or distal position of FIG. 47A, with the non-expanded(collapsed) stent structure 1612 distal of the coupler 1548, i.e.,spaced further from the coupler 1548. After insertion of the catheter1510 to the desired position with respect to the target tissue, thecatheter 1614 is retracted proximally within the lumen 1513 of catheter1510 to retract the stent structure 1612 axially toward the distalcoupler 1548 to the position of FIG. 47B. In the illustrated embodiment,the stent structure 1612 is retracted adjacent the distal coupler 1548,either slightly spaced or in abutment. In alternate embodiments, thestent structure 1612 has an opening like opening 1586 of balloon 1583dimensioned to fit over the distal coupler 1548 so the stent structure1612 can be retracted to overlie the distal coupler 1548. Onceretracted, the push/pull rod 1616 is pulled axially (or further pulledif partially pulled prior to retraction) to expand stent 1612 to fillthe transverse dimension within the body space, e.g., colon, as shown inFIG. 47C to stabilize the chamber. The retractor elements 1552, 1554 aremoved to the expanded position, bowing outwardly, in the mannerdescribed above, e.g., by movement of an actuator operatively connectedto the retractor elements 1552, 1554 to form the chamber for workinginstruments. As noted above, the retractor elements 1552, 1554 can beexpanded before or after proximal movement of the stent structure 1612toward the distal coupler 1548 and before or after expansion of thestent structure 1612.

Note as an alternative to pull rod 1616, the catheter 1614 can include apusher and the stent 1612 is retained in a collapsed position within thecatheter 1614. When the catheter 1614 is moved to the desired site, thepusher is advanced distally to force the stent 1612 out of the distalend of the catheter 1614 to enable it to automatically expand to theexpanded position of FIG. 47C due to its spring like characteristics orits shape memory material.

In an alternate embodiment, catheter 1614 is axially fixed withincatheter 1510 and the stent structure 1612 is therefore axially fixedwith respect to the distal coupler 1548, positioned distally adjacent oroverlying coupler 1548. Thus, in this embodiment, the stent 1612 is inthis fixed axial position when collapsed and inserted and remains in thefixed axial position when expanded.

FIGS. 49A and 49B illustrate an alternate embodiment wherein the distalballoon forms both the stabilizing structure and the distal coupler. Asshown, system 1620 has two flexible elements 1622, 1624 attached attheir proximal ends to proximal coupler 1626 of catheter 1628. At theirdistal ends, flexible elements are attached to stabilizing balloon 1630.One of the flexible elements 1622, 1624 has a lumen for passage ofinflation fluid to inflate the balloon 1630. A C-shaped securementmember 1632 can be provided within the balloon 1630 to provideattachment structure for the flexible elements 1622, 1624. In use, thecatheter 1628 is inserted with balloon 1630 in the collapsed position ofFIG. 49A. When at the desired site, the balloon 1630 is inflated and theflexible elements 1622, 1624 are expanded (either subsequent or prior toballoon expansion) to the position of FIG. 49B, with the balloon 1630filling the transverse dimension of the body lumen as in FIG. 43C andstabilizing the chamber formed by the flexible elements 1622, 1624. Inall other respects, catheter 1628 is the same as catheter 1510 andallows passage of the endoscope and passage of the tool channels andworking instruments into the chamber.

In the foregoing embodiments of FIGS. 43A-47C and 49A-49B having astabilizing structure, two flexible elements are disclosed to form anasymmetric chamber. It is also contemplated that four flexible elementscan be provided to form a symmetric chamber as shown for example in FIG.48 . In this embodiment, the four flexible elements 1642, 1644, 1646,1648 of catheter 1640 are attached at proximal ends to proximal coupler1654 and with distal ends to distal coupler 1566. Transverse bridgemembers 1643 spanning the retractor elements can be provided forstabilization. The flexible elements 1642, 1644, 1646, 1648 are insertedin the collapsed position as shown. When at the desired site, they areexpanded to form a substantially symmetric chamber, expanding the wallof the body lumen in opposing directions. A stabilizing element such asthe illustrated balloon 1648 attached to catheter 1652 is expandable tostabilize the chamber in the same way as the balloons described above.Alternatively, a mechanical expander as described above instead of aballoon can be utilized to stabilize the chamber.

The expansion of the stabilizing structure can occur prior to or afterexpansion of the retractor elements 1642, 1644, 1646, and 1648. Thecatheter 1652 can be movable axially to adjust the axial position of theballoon 1648, or alternatively axially fixed, in the same manner asdescribed above.

Note one or more transverse bridges between the flexible elements 1522and 1524 (or 1642-1648) can be provided in any of the foregoingembodiments to provide stabilization during bending and facilitatecontrolled spaced expansion/reshaping.

The use of the systems in FIG. 43A-49B is shown for removing a lesion,such as a polyp, from a colon wall. However, it should be understood,however, that the systems can be used for other procedures within thecolon or the gastrointestinal tract, as well as used for otherprocedures in other body lumens or body spaces of a patient.

Note movement/actuation of the components of any of the embodiments canbe robotically controlled including for example expansion of theretractor elements, axial movement of the catheter, expansion of thestabilizer structure and/or inflation of the stabilizer balloon.

Referring to FIG. 36 , the retractor elements of the embodimentsdisclosed herein forming an asymmetric cage create a working space orworking chamber for performance of the surgical procedure. The chamberfacilitates instrument maneuverability, for example instruments'triangulation as described above. Note the asymmetric chamber causes areconfiguration of the body lumen or working space without stretchingthe body lumen wall beyond a point when it can be injured, e.g.,lacerated by the stretching force. Such reconfiguring can be appreciatedby reference to FIG. 36 where the body lumen has changed from asubstantially circular cross-sectional configuration to a somewhat ovalshape configuration where the walls are elongated as shown. As can beappreciated, this increases the distance from the tips of the workinginstruments to the targeted tissue, such as the polyp C on the wall ofthe colon B. Thus, the retractor elements change the colon shape at thedesired site to a narrower width, particularly at the bottom of thechamber, and taller in height (in the orientation of FIG. 36 ) toincrease working space for the instruments thereby reconfiguring thecolon lumen.

The retractor elements of the embodiments disclosed herein alsostabilize the luminal wall motion which may be more prominent in thegastrointestinal tract. This may facilitate the surgical procedure,particularly in the gastrointestinal tract.

Note that the various embodiments of the cage described above areexpandable to alter the working space within the body space or bodylumen. As the cage is expanding, the working space around the targettissue, e.g., lesion, is increasing. More specifically, the distancebetween the instruments and the target tissue is increasing, hence,facilitating the instruments' maneuverability and ability to performmore advanced surgical techniques inside the lumen, e.g., tissueretraction, dissection, repair. As the cage expands it may press on anddeflect at least a portion of the luminal wall. As a result, the shapeof the lumen can be changed depending on the size and shape of the cage,the extent of its expansion and the size and shape of the body lumen. Insmaller diameter body lumens, such as the bowel, the expansion of thecage may substantially reshape the body lumen as described above. Thisreshaping can also occur in larger diameter body lumens. However, itshould also be appreciated that in certain larger diameter body lumens,such as the stomach, and especially when insufflation is utilized forthe surgical procedure, the body lumen may not necessarily be reshaped.For example, the cage may only contact one side of the body lumen wall.However, even in this case, the expanded cage applies a radial forceagainst the body wall to alter the working space. Therefore, whether thecage is used in small or larger diameter working spaces/lumens itadvantageously moves at least one side of the wall to increase thedistance between the tips of the instruments and the target tissue,thereby functioning as a working space expanding system to facilitateaccess and maneuverability as described in detail above. As can also beappreciated, the dynamic nature of the cage with its controlledexpansion enables the system to function as an organizer to adjust andoptimize the distance between the tips of the instruments and the targettissue. Also note that in larger diameter body lumens a symmetric cagemight also be able to be utilized, although not optimal.

Note the endoscopic instruments can be used for partial tissueresection, for example, submucosal or subserosal resection. Theendoscopic instruments could also be utilized for full thickness tissueresection. The instruments enable removal of the lesion with healthytissue margins, thereby providing a complete, en-block removal of thepathological lesion.

Without intending to be limited to any theory or mechanism of action,the above teachings were provided to illustrate a sampling of allpossible embodiments rather than a listing of the only possibleembodiments. As such, it should be appreciated that there are severalvariations contemplated within the skill in the art that will also fallinto the scope of the claims.

We claim:
 1. An endoscopic system, comprising: a flexible cathetercomprising a proximal portion and a distal portion; a plurality offlexible elements extending along a length of the flexible catheter; adistal coupler coupled to distal portions of the plurality of flexibleelements; and an expandable member associated with a distal end of theflexible catheter, wherein the expandable member configured totransition from a deflated state to an inflated state, and wherein theexpandable member comprises a central opening with dimensions sized tofit over outer dimensions of the distal coupler.
 2. The endoscopicsystem of claim 1, wherein the flexible catheter includes a lumenextending therethrough and in fluid communication with the expandablemember to inflate the expandable member to transition from the deflatedstate to the inflated state and to deflate the expandable member totransition from the inflated state to the deflated state.
 3. Theendoscopic system of claim 1, wherein the expandable member has adonut-shape configured.
 4. The endoscopic system of claim 1, wherein theexpandable member is moveable distally beyond the distal coupler.
 5. Theendoscopic system of claim 1, wherein in the inflated state theexpandable member is configured to stabilize the plurality of flexibleelements within the body lumen.
 6. The endoscopic system of claim 1,wherein the plurality of flexible elements are moveable to form aworking space within the body lumen, the endoscopic system comprising aflexible instrument extending a length of the flexible catheter, whereinthe flexible instrument is rotatable and movable to an angled positionto orient a distal end of the flexible instrument within the workingspace.
 7. The endoscopic system of claim 1, wherein the plurality offlexible elements are movable from an insertion position to an expandedposition to atraumatically engage tissue of a body lumen to render aworking space in the body lumen in an asymmetric configuration.
 8. Anendoscopic system comprising: a primary catheter comprising a proximalportion and a distal portion; a flexible catheter disposable in theprimary catheter, the flexible catheter comprising a proximal portionand a distal portion; a plurality of flexible elements disposable in theprimary catheter and extending along a length of the flexible catheter;a distal coupler coupled to distal portions of the plurality of flexibleelements; and an expandable member associated with a distal end of theflexible catheter, wherein the expandable member configured totransition from a deflated state to an inflated state, and wherein theexpandable member comprises a central opening with dimensions sized tofit over outer dimensions of the distal coupler.
 9. The endoscopicsystem of claim 8, wherein the flexible catheter includes a lumenextending therethrough and in fluid communication with the expandablemember to inflate the expandable member to transition from the deflatedstate to the inflated state and to deflate the expandable member totransition from the inflated state to the deflated state.
 10. Theendoscopic system of claim 8, wherein the expandable member has adonut-shape configured.
 11. The endoscopic system of claim 8, whereinthe expandable member is moveable distally beyond the distal coupler.12. The endoscopic system of claim 8, wherein in the inflated state theexpandable member is configured to stabilize the plurality of flexibleelements within the body lumen.
 13. The endoscopic system of claim 8,wherein the plurality of flexible elements are moveable to form aworking space within the body lumen, the endoscopic system comprising aflexible instrument disposable in the primary catheter and extending alength of the flexible catheter, wherein the flexible instrument isrotatable and movable to an angled position to orient a distal end ofthe flexible instrument within the working space.
 14. The endoscopicsystem of claim 8, wherein the plurality of flexible elements aremovable from an insertion position to an expanded position toatraumatically engage tissue of a body lumen to render a working spacein the body lumen in an asymmetric configuration.
 15. An endoscopicsystem system, comprising: a flexible catheter comprising a proximalportion and a distal portion; a plurality of flexible elements extendingalong a length of the flexible catheter; a distal coupler coupled todistal portions of the plurality of flexible elements; and an expandablemember associated with a distal end of the flexible catheter, whereinthe expandable member has a donut-shaped configuration with a circularcentral opening having a first dimension, wherein the distal coupler hasa circular shape having a second dimension smaller than the firstdimension, wherein the expandable member is configured to transitionfrom a deflated state to an inflated state, and wherein the flexiblecatheter comprises a bend configured to position the central opening tobe moveable over the distal coupler.
 16. The endoscopic system of claim15, wherein the flexible catheter includes a lumen extendingtherethrough and in fluid communication with the expandable member toinflate the expandable member to transition from the deflated state tothe inflated state and to deflate the expandable member to transitionfrom the inflated state to the deflated state.
 17. The endoscopic systemof claim 15, wherein the expandable member is moveable distally beyondthe distal coupler.
 18. The endoscopic system of claim 15, wherein inthe inflated state the expandable member is configured to stabilize theplurality of flexible elements within the body lumen.
 19. The endoscopicsystem of claim 15, wherein the plurality of flexible elements aremoveable to form a working space within the body lumen, the endoscopicsystem comprising a flexible instrument extending a length of theflexible catheter, wherein the flexible instrument is rotatable andmovable to an angled position to orient a distal end of the flexibleinstrument within the working space.
 20. The endoscopic system of claim15, wherein the plurality of flexible elements are movable from aninsertion position to an expanded position to atraumatically engagetissue of a body lumen to render a working space in the body lumen in anasymmetric configuration.